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Soundmanpt 19 Oct 2017, 08:52

Carrie

You have mentioned about Danielle going in twice recently to get her eyes checked. I'm a bit surprised that Vickie didn't want to go along to get her eyes checked as well. She has had her current glasses for well over a year now and knowing how much she enjoys wearing her glasses I would think she would be hoping to get an increase as well as new glasses by now. Next time a glasses conversation comes up with Danielle and Vickie is around you should ask Vickie when she is due to get her eyes checked again.


Cactus Jack 19 Oct 2017, 08:04

JC,

Everyone is different, so it is possible. She could also have some allergies to things such as pollen and glasses may help minimize how many allergens get in her eyes. No way to really tell the cause of the bloodshot eyes without a complete examination and tests.

C.


JC 19 Oct 2017, 07:53

Has anyone heard of red bloodshot eyes simply from not wearing needed glasses? I saw a video of a nearsighted girl who didn't wear glasses for about 15 minutes. I noticed red eyes and she said that happens when she doesn't wear glasses for chunks of time. I'd estimate her prescription in the -6 to -8 range, and she also mentioned astigmatism. She never wears contacts. My only guess is eyestrain from the astigmatism -- I'm nearsighted and have gone much longer stretches then that and never get red eyes from it.


Cactus Jack 14 Oct 2017, 10:13

WeirdVision,

I don't have enough information or knowledge to make any more suggestions. There is no way I can experience what you are seeing. My suggestion is to try to write down what you had been doing for 10 to 15 minutes prior to the event and collect enough data to see if there is anything in common that leads up to the event. Also, try to discover if there is anything that seems to cause your vision to go back to normal.

Discovering the source of a problem is like being a detective. You have to look for clues that may lead you to solving the problem.

Good Luck!

C.


WeirdVision 13 Oct 2017, 20:04

The old glasses thing has never been mentioned. Also no subject really involves close work, I just do homeowrk at a usual distance. I am not much of a reader.


Cactus Jack 13 Oct 2017, 14:49

WeirdVision,

You are right. It is weird. The only things in your vision system that can change rapidly are your Ciliary Muscles and Crystalline Lenses. They are the optically active part of your Eye's Lens system that allows you to focus, similar to the auto-focus system on a camera.

There are two types of Myopia. Axial or True Myopia, which is caused by a mismatch between the total optical power of your eye's lens system and the length of your eyeballs The other type is Pseudo or False Myopia, which is caused by the Ciliary Muscles having difficulty fully relaxing for distance. Both types can be present and their effects add together. It is the Ciliary Muscles and Crystalline Lenses that compensate for Minus over correction that is the first step in Inducing Myopia.

The reason I asked about dilation is that one of the effects the dilating agent has is to temporarily paralyze your Ciliary Muscles so they cannot affect the results during an exam. However, the agents that are typically used are not very strong so they will wear off in just a few hours. If a person has been wearing much more minus than that need for full correction, the dilating agent may not have time to fully relax the Ciliary Muscles.

Where I am going with this is that if your Ciliary Muscles are under constant stress they can occasionally spasm or involuntarily relax. That might cause an effect similar to a zoom lens on a camera.

You mentioned that you were 18. I assume that you are in school and likely do a lot of studying and close work. Has your ECP ever suggested that you use an older, weaker pair of glasses for close work or any form of reading glasses to reduce your focusing stress? May I ask the subjects that involve a lot of close work?

C.


WeirdVision 13 Oct 2017, 09:29

I live in America, and yes I have a had a dialated exam. I am not sure what my first prescription was at all. Sorry.


Cactus Jack 12 Oct 2017, 21:29

WeirdVision,

I keep thinking of questions.

You said that you started wearing glasses 4 or 5 years ago, to you remember what your first prescription was? Exact would be nice, but close would be helpful.

BTW, You need to understand that I am not an Eye Care Professional (ECP). I am an Amateur in the original sense of one who studies a subject out of love. In my case it was somewhat out of necessity. My background is Electronic and Computer Engineering (IOW "Problem Solving"). I just turned 80 and have been dealing with vision problems since my early teens. I was not satisfied with the answers ECPs gave me to explain my vision problem and I started studying about it.

These days, the word Amateur has a bad connotation. Many of the scientific principles we use today, were discovered by "Amateurs" such as Sir Isaac Newton, Voltaire, etc. I am far from being in that class, but I have earned a reputation as being a pretty good explainer.

C.


Cactus Jack 12 Oct 2017, 16:05

WeirdVision,

Sorry to keep asking questions.

May I ask where your live (country)?

Have you ever had a dilated eye exam?

C.


WeirdVision 12 Oct 2017, 10:44

My prescription is -7.75, -1.25 and -6.75 and -1.00


Cactus Jack 12 Oct 2017, 09:46

WeirdVision,

I am wondering if your Ciliary Muscles could be having occasional spasms. Could you post your complete prescription?

C.


WeirdVision 12 Oct 2017, 06:46

I have never experienced vertigo. Just what I mentioned earlier. To go a little more into detail, what happens is I see something and all of a sudden it is like it zoomed in and then it quickly zooms out. Sometimes it is like my point of view changes for a split second. Sometimes (not that much) it is like everything moves quickly (I only see a blob of color) and then goes back.


Cactus Jack 11 Oct 2017, 22:06

WeirdVision,

I don't believe it would be called "normal" by any stretch. My experience with apparent undesired motion is related to the Eye Muscle Control System and its connection to the semi-circular canals (balance sensors) in your ears. I have had occasions where the tiny crystals in my semi-circular canals got out of position and caused sensations of Vertigo and subsequent random eye motion that made the room appear to be moving around. Have you had any thing like that happen?

If that is the source of the problem, it happens often enough that there is an Epley Maneuver of gently moving the head so that gravity will move the tiny crystals in the semi-circular canals back where they belong.

C.


WeirdVision 11 Oct 2017, 19:03

Hi,

I have a question, for a while now I have noticed that sometimes I am looking at something and then it is as if it moves, goes further away or comes closer, sometimes even moves horizontally. I have no control over it, it just happens and I cannot make it happen either. Is this normal? If not why is it happening?

A little about me, I am an 18 year old nearsighted female (it happens both with and without glasses). I have had glasses for 4 to 5 years now, and I needed them for a while before I got them.


antonio 01 Oct 2017, 07:49

Question,

Maybe you have an eye infection,

you might need some antibiotica to put into your eyes

to cure it, please go to an eyedoctor to check.

if so itīs infectious and you could infect your family and people at work with it,

after you touched your eyes and then opening a door.

It should be cured soon, so donīt do nothing for a week or more, please

do you wear contacts ? then donīt do that for now, please.

so donīt you wear glasses full time ?

best regards, antonio


Question 01 Oct 2017, 07:31

Hi I have a question and am not quite sure where it fits, so sorry if you think it does not belong in the vision thread. To get to the point, for the last couple of months or so I have noticed when I wake up I have a lot of sleep in my eyes. Before that I used to hardly ever have sleep in my eyes when I woke up and when I did it was not much at all. Now it is like my eyes are glued shut sometimes, and sometimes it starts forming before I even go to sleeo. Also along with this I have noticed my eyes have been really watery too and very itchy here and there and when I itch them sometimes it hurts to touch. Lastly along with all this sometimes when I am on my phone as I am blinking I see two of all the text. Like a back layer is being streched out from the main text. This usually happens at night or in the morning though. I feel like it might just be looking through my eyelashes, but still I find it a bit alarming. It has happened with and without my glasses on. In all, I guess I am wondering is there something wrong with my eyes and what does all this mean or is it just a few unrelated things that don't mean anything.


NNVisitor 28 Sep 2017, 19:31

David/Soundmanpt

Nearsighted people typically have no problem reading books or other printed materials without their glasses on. Even many with high myopia can do so but need to hold things closer to their eyes. David's wife developed the habit of full time wear which is good for her except around steam while cooking and on a rainy day.I try to distance myself from the steam or at least my face with glasses on. In summer I wear a baseball cap which often can sheild glasses from the raindrops. Of course a person showing up to work at an office probably would look a little out of place wearing a baseball cap to work.


Soundmanpt 28 Sep 2017, 07:51

David

I'm not really surprised that your girlfriend is still finding some things that she wasn't able to see or not see very well before she got her glasses. Probably as her eyes were slowing getting worse she wasn't even trying to see somethings anymore. So once she began to not be able to see things at a distance she just didn't bother. You have to remember even though you and her now have nearly the same prescription the way you both got there is completely different. Your first glasses were quite weak if you recall. You had a couple increases to get to where your at now. Your girlfriend didn't take the slow rode to where she is now. So she went from having perfect vision to where she is now. That's a pretty big jump. Now i'm sure she feels nearly blind without her glasses. Of course she isn't but her eyes have really changed from being perfect like she once was. I'm sure her job is the main reason. The good thing is she apparently always wanted to wear glasses. She's probably not thrilled that her eyesight is as blurry as it is without glasses now. But that's why I asked you if now that the newness of wearing glasses has wore off if she maybe has become more unhappy about wearing glasses once she found many of the things most people complain about. She has found a couple things annoying to her. I'm sure trying to cook when her glasses fog up has to be challenge. Taking her glasses off shouldn't be a problem for her because she should be okay seeing close up without her glasses except for seeing the timer across the kitchen. Trying to watch TV and get comfortable lying down is a very common problem for most glasses wearers. You almost need strap on sports goggles. You both need to try to make sure you take your glasses off before falling asleep. because you could wake up and find your glasses broken. If they come off in your sleep you could roll on them and break them. Your girlfriend isn't cleaning her glasses as much because she has adjusted to her glasses. Even though she was fine with getting glasses she still had to get used to wearing them full time and her eyes had to get used to seeing everything through lenses in front of her eyes. I doubt that her glasses really needed to be cleaned so much but rather just learning to wear glasses. I know you said a while ago that once your girlfriend got used to wearing glasses she rarely took them off anymore which is fine but you both should be able to read a book comfortably without your glasses? The computer is different of course so she does need to wear her glasses for that. But if both bale to read without your glasses you really should try and remember to take them off when you're doing a fair amount of reading. Also have you seen your girlfriends sister since she headed off to college? How is she doing with her glasses? When you were helping er pack to leave you said she was wearing her glasses all that evening. Is she pretty much wearing her glasses full time as well?


David 27 Sep 2017, 16:17

Soundmanpt

It has been around 4 months now but every once in a while my girlfriend will still point out something that she couldn't see or was difficult to do before she had glasses. We both watched the game last night and she is really getting into hockey which is pretty awesome and I'm sure that being able to see the game made all the difference from last year lol. It's great that she is a sports fan, actually she is probably a bigger sports fan than I am and now that she seems to be getting into hockey I'm sure we'll end up going to a few games this season. When I tried to watch the game without my glasses I found it horrible so I'm pretty sure that's why she never enjoyed hockey. Baseball is much slower and the way the plays are shown on TV makes it pretty easy to see even without glasses so I'd bet that's why she had no problems watching baseball even with her uncorrected vision the past few years. We are both completely used to wearing glasses now, in fact, I don't think I've work my contacts at all outside of the gym/sports since we got our glasses. It's pretty much second nature now to grab my glasses first thing in the morning and my girlfriend is the same way, they are just right there on the dresser next to the bed so it is easy to grab them right after waking up. Now that she has had glasses for a couple months she doesn't really complain about them getting dirty anymore however there are a few things that annoy her about having to wear glasses all the time. The biggest thing she complains about is having them fog up when she is cooking. The heat from the oven and the steam from the stove can make it really difficult to see properly when cooking and sometimes she will get fed up and just take her glasses off. It's not too much of a problem since most of cooking is up close but the timer we have is on the microwave on the other side of the room and without glasses on neither of us can really see it from the stove lol. The other thing that we both find annoying is that it can be hard to lie down and watch a movie or read a book comfortably and if we try to cuddle they can get in the way sometimes too lol. Also, we've both fallen asleep with our glasses on a few times, usually while watching tv, and that is always awful too. It sucks to wake up and have a sore nose or worse having them knocked off and you have no idea where they went.

NNVisitor

That sounds like what I used to do in high school, I didn't like my glasses at all and didn't use them much until my prescription got bad enough and I got contacts. It was difficult enough to try and watch the game on TV without glasses on, I can't imagine trying to see the puck from the seats in a stadium. I'm not sure what your prescription is but at -2.25/-1.75 I'm pretty sure that I wouldn't be able to see the puck at all especially since I tend to get cheaper seats lol. I remember when I first got glasses I didn't wear them to the game but I brought them with me and I was really glad that I did.


NNVisitor 26 Sep 2017, 21:49

David

When I was young I rarely watched TV with my glasses on. Instead I sat close to the screen. In retrospect that certainly was not good for my eyes.

I went to some real NHL games live back in the days when Bobby Hull played and Glenn Hall was the Chicago goalie. I didn't wear my glasses and was absolutely lost as to who had the puck.

My highlight was getting autographs outside their dressing room after the game. They and others on the team signed a program that I had. Unfortunately I don't have that program with all the signatures from the Chicago team back then in the 1960's.


Soundmanpt 26 Sep 2017, 11:53

David

Nice to hear form you. Always nice to get an update on how the two of you are doing. I guess there are still some things that your girlfriend is still finding out how much wearing glasses makes a difference to her. It seems watching hockey is one of them. So you now have a girlfriend that sine she can see seems to enjoy watching hockey. She already enjoyed watching baseball even without being really able to see it very well until recently. I think your one lucky guy to have a girlfriend that seems to enjoy sports. That's what every guy wants I think. It makes sense though, if she wasn't able to see the puck it would be very hard for anyone to enjoy watching hockey. I just looked back she got her glasses near the end of May. So she has had her glasses for about 4 months. You would think in that much time she would have found everything that she wasn't seeing properly by now but she is still finding things that she had been missing out on. By now you both should be used to wearing your glasses without much thought about them. I know she was actually excited about getting glasses and the only time she she seemed less than confident about wearing her glasses was shortly after she got them and you were about to have dinner with her parents and sister. She was even considering taking her glasses off before going in but you convinced her to keep them on. If you hadn't been their supporting her she probably would have taken them off. Otherwise she must have been fine with others seeing her wearing glasses for the first time. Now that the newness of having glasses has worn off a bit has she even complained about her glasses at all? By now i'm sure she has encountered things like rain and things like going from cold to warm and having her glasses fog over. Or maybe trying to get comfortable laying down trying to watch TV and having her glasses get mashed against her face.

So now I guess you and her will be going to some hockey games? I'm looking forward to hockey as well. Not a great year for baseball around here. I'm hoping the Cardinals go after Stanton. Do you know we haven't had a 100RBI guy since Albert left?


Lou 26 Sep 2017, 09:55

Hi Paul

Thank you very much for your response and further clarification.

When you mention my example, I guess that you are referring to me quoting my own prescription. In my case, although my refractive error is very small, I can see better when adding correction, with my visual acuity improving from 6/6 in each eye to 6/5+1. As well as greatly reducing eye strain, I do also notice an improvement in my eye sight at all distances with my glasses. I therefore believe that my hypothetical person is someone with either no refractive error, or one so small, that adding any correction does not improve their acuity at all. In both these cases, as you say, their best corrected vision would be with zero sphere and zero cylinder correction.

For this hypothetical person, I both fully understand and agree with your explanation, that a -0.50 correction would not result in them seeing distances more clearly, and would result in a slight deficit in their near vision.

Best wishes

Lou


Paul 25 Sep 2017, 20:17

Lou -- delayed response to your September 9 post, with this question: "Would this result in slightly better long distance vision at the deficit of slightly worse close vision, or more specifically, would this move the far point of focus further out at the deficit of also moving the near point of focus further out?"

Your hypothetical was a person "with no refractive error." I think this would mean (but this is worth checking) that the person has their best corrected acuity with zero sphere and zero cylinder correction; they can't see any better by adding correction, though they might see equally well with certain small corrections (including your example). So your question is basically whether a -0.50 correction would change what this person sees. At distance, their eye would have to accommodate the half-diopter for the image to be focused clearly...most people can do this easily. Would they see more or less clearly? Definitely not *more* clearly, as defined by the hypothetical scenario...if the -0.50 made things clearer, then the person DOES have a refractive error. And I would guess not *less* clearly either; 0.5 diopter creates hardly any minification and the eye's focusing mechanism doesn't add much astigmatism.

At near, the -0.50 would hurt this person's ability to see close up, but only slightly.


David 25 Sep 2017, 16:11

It's been a couple of months since I last posted but something kinda funny happened last night. I was watching the hockey game and my girlfriend decided to sit down and watch it with me. She has never really been into hockey and usually doesn't ever watch it at all. However, last night she was really getting into the game and seemed to be really enjoying watching it, even asking me about the rules and other stuff during the game. After the first period I said something like I didn't think you liked hockey that much. She replied that she never knew it was that exciting to watch because she always had a hard time following what was going on and couldn't understand what was happening during the game. It occurred to me that this was probably the first time she had seen a hockey game since she got her glasses earlier this summer and that she probably couldn't see the puck too well before. When the second period started I took off my glasses to see how hard it would be to watch that way and it was really hard to follow the action and even harder to see the puck properly. My girlfriend must have seen me squinting and making funny faces at the TV while trying to see the game because she just burst out laughing and said that about sums up her experience watching hockey before last night. I tried to last as long as I could without my glasses but gave up after about 5 minutes and threw my glasses back on lol, I can't imagine trying to watch a whole game like that. She seemed to really enjoy the game which is amazing because I'm a really big hockey fan and she even sounded interested in going to a few games once the regular season starts. Even after 4 months she is still discovering little things that make her glad she got glasses even more lol.


Cactus Jack 24 Sep 2017, 06:26

Vision occurs in the brain. 3 D vision requires 2 very slightly different images from your two eyes that are spaced only 6 to 7 cm (2.3 to 2.8 inches) apart. It is something the brain has to learn how to do. If the images are very different in size on the Retina, it is much harder to do. It is even possible for a person who has vision in only one eye to develop a sense of spatial relationships, usually related to object size, but it takes time process the image. Poor 3 D vision makes it difficult to play ball sports because of the time required to process the image(s). By the time you figure out where the ball is, it is too late to do anything about it.

Even excellent vision with both eyes, does not always provide accurate spatial relationships (3 D). Consider optical illusions that use object size to deceive the brain into thinking something is not where it seems to be or not the object appears to be.

IF a person has vision in both eye AND If there is a significant difference between the two images, the brain will typically select the best image and use that as the primary vision source and either ignore the other image completely (e.g. Amblyopia) or pick up a few additional visual clues from the other image.

3 D imaging methods, where two separate images are delivered to the Retinas, using physical separation (View Master or Stereopticon devices) or optical separation (polarized or red/blue glasses) are excellent training devices.

There have been cases where a person was unable to see 3 D and suddenly developed the ability. I know of two, but there are probably more. One was on TV where a woman in her 40s, who had Amblyopia, was driving and suddenly the brain turned on the previously “blind” eye. As she described it, the steering wheel suddenly appeared to jump out at her and from then on she had 3D vision. The other was one of our members who was severely cross-eyed because of some missing eye muscles. He also did not have all the lenses in his eyes, probably because of Rubella during gestation. He had to wear very high Plus glasses with lots of prism. I don’t remember the exact circumstances, but one day the two images matched up enough that he suddenly saw one 3 D image. It didn’t last very long, but as he described it, “It scared the hell out of me”.

If there is a considerable difference in the prescription for each eye, contact lenses, which minimize Vertex Distance effects on image size, can often provide good 2 D vision. One very important thing to remember is that everyone is different and a solution that works for someone else may not work for you.

C.


Crystal Veil 24 Sep 2017, 01:52

Weirdeyes,

I have always been exactly on the threshold you mention and your assumption is right. No 3 D vision at all for me. As a result, no driving license either. Over the years, my prescription shifted from minus to mainly plus but the four diopter gap always remained the same. I have done mountain climbing all my life. No vertigo at all.


Weirdeyes 23 Sep 2017, 21:40

At what degree of anisometropia do people no longer have depth perception? I have 3 diopters of it and I can still watch 3D movies without glasses so I do have some depth perception. But I do fail all depth perception tests and can't deal with ball sports. So my depth perception isn't too great. I have no trouble passing depth perception tests with my glasses. When I'm only wearing my right contact lens, which gives me 4D difference between my eyes I do notice my depth perception is absolutely terrible. So maybe 4D is the threshold instead of 2 or 3 like I've heard.


Gregin Colo 18 Sep 2017, 20:15

Thanks Ric for the article you shared, very interesting and informative. Especially interesting to me was section 5 showing the lenses profiles for varying degrees of high myopia.


ric 18 Sep 2017, 03:47

Tom, here they explain how the lenses distrance from the eye varie the correction:

http://www.pointsdevue.com/article/high-myopia-specificities-refraction-and-optical-equipment#tab2

For high myopes is pretty notticeable, i can read well small prints just moving 2 mm my glasses.


Weirdeyes 16 Sep 2017, 22:42

Tom

I think people with stronger minus can increase their prescription a bit by wearing their glasses closer to their eyes. Low minuses can't really do that.


Tom 16 Sep 2017, 22:32

Having lunch with colleagues last week, and a female coworker who had not joined us the day before told us it was because she had been to her ophtalmologist for a check-up. She was surprised that he prescribed her an increase from -5.5 to -7.0, as she had not expected such big raise because not having real problems seeing with her -5.5 glasses.

It told this to my partner in the evening, and she could hardly believe it. She is myopic herself, but only with -1.5, and she said a same change for her, from -1.5 to -3.0, would be a huge increase, and she could not imagine my coworker not having had big trouble with her -5.5 lenses while in fact needing -7.0.

We had a long discussion about this, and my idea was that a 1.5 increase from -5.5 to -7.0 is indeed less "brutal" for a person, than a same 1.5 increase from -1.5 to -3.0, because the latter is x2 and the former "only" x1.27. My partner did not agree, saying an increase of 1.5 is as bad and vision-wise identical for anybody whether starting from -1.5 or -5.0. She said she sometimes try on colleagues' glasses when someone comes with new frames to the offices, and she can really tell the difference between looking through -3.0, -6.0 or higher.

So can you help? Does a 1.5 increase make the same difference for a -1.5, a -4.0 or a -6.0 person?


Stavy 14 Sep 2017, 10:38

Okay, I will let my doctor know. I am studying biomedical engineering.


Cactus Jack 11 Sep 2017, 10:19

Stacy,

It is very difficult to offer a suggestion. I am assuming the double vision with Red text is occurring primarily when you are reading. It could be caused by convergence problems related to the location of the optical center ("sweet spot") of the lenses or actual convergence issues. With high prescription lenses, the best visual acuity and least distortion occurs when looking thru the optical center of the lenses. When you read, your eye have to converge and you are not looking thru the "sweet spot" and any chromatic aberration in your glasses will be more apparent.

The plastic lens material with the best Abbe (aberration) number is CR-39. It also has the lowest Index of Refraction of about 1.49. That unfortunately means that the lenses will be thicker than the materials with a higher index. It is very tempting for people who need high prescriptions to order glasses with high index lenses to make the lenses thinner, but the downside of the lenses is that they can have some optical issues.

I think you should talk to your ECP and tell him/her about your double vision issues.

May I ask what you are working on in Grad School?

C.


Stacy 11 Sep 2017, 06:06

So, I should not be worried about seeing double with red print? Just want to make sure because I am still slightly confused. I am 22 and am currently working part time and going to Grad School full time.


Cactus Jack 10 Sep 2017, 16:19

Stacy,

If your prescription is written in the traditional order it

OD Right Eye Sphere -8.25, Cylinder -2.00, Axis 170

OS Left Eye Sphere-8.75, Cylinder -1.75, Axis 125

There can be a few optional things after that, such as Prism (BO, BI, BU or BD), Add or special instructions and maybe PD (Pupillary Distance).

I doubt if the pinhole glasses have much chance of working. To amplify what Antonio said, you need ONE very small pinhole. It is very unlikely that you could do both eyes at the same time without seeing double.

The red print issue is not uncommon if you have prism in your glasses. With your prescription you could see some color displacement and color fringing if you look thru the lens, away from the edge, because of how lenses work.

One of the uses for a prism is to break up a beam of white light into its component colors. If you look at a prism end on, you will notice a point called the Apex. The surface opposite the Apex is the Base of the prism.

A lens is used to bend light rays. If you can imagine this, a MINUS lens consists of an infinite number of very thin prisms arranged in a circle with their Apexes in the center and the Bases on the outside. A PLUS lens is the opposite with the prism bases in the center and the Apexes outside. When light passes thru the lens it gets broken up into its component colors of light. Blue light gets deflected the most and Red light is deflected the least, but the eye is actually more sensitive to red than blue and so it is more noticeable. The amount of the deflection is determined by the prescription.

May I ask your age and occupation?

C.


antonio 10 Sep 2017, 06:45

Hi Stacy,

Such high prescriptions are difficult to correct using pin hulole glasses maybe. If so they should be used in good daylight and with very small pinholes

Best regards, antonio


Stacy 09 Sep 2017, 14:33

Oh, my prescription is -8.25 and -8.75 and some other numbers, but that is what my doctor said in the last exam, and he said the other numbers were for something else I cannot remember. According to the card the numbers are -8.25, -2.00, 170, -8.75 -1.75, and 125.


Stacy 09 Sep 2017, 14:28

I see double usualy with like red print for some reason. I never thought much about it, that is the only times it happens.


Cactus Jack 09 Sep 2017, 13:30

Stacy,

It would be helpful if you posted your complete prescription.

The double vision thing, with the pinhole glasses, is probably related to how the Eye Position Control System (EPCS) works. You may have a bit of Strabismus, where your eyes would like to point in slightly different directions, many people do. It is sometimes called Muscle Imbalance, as a catch-all name.

If the EPCS has two good images to work with, it can typically fuse the two image, if they are moderately displaced, in a fraction of a second without your being aware that it is doing it. If the Strabismus is high enough to cause difficulty in fusing the images or maintaining fusion, you may need some Prism correction in your glasses. (I do).

There are some simple tests that you can do at home to get a good idea of how hard your EPCS is working to fuse images.

If you don't have problems with double vision when wearing your glasses, don't worry about it.

C.


Stacy 09 Sep 2017, 11:20

I am nearsighted, I wear my glasses most of the time, I thought the pinhole glasses were supposed to make everything clear like my glasses do, but it was hard to see in those because the grid was in the way and I would see double of everything.


Lou 09 Sep 2017, 10:57

Hi Paul

Re, your following post, could I ask you a few questions, which I'd please be interested in your response:

Soundmanpt, please stop suggesting a person with 20/20 vision c an get 20/15 vision by wearing -0.50 additional correction. It does not work that way. Everyone has some "best corrected visual acuity", at which most people see 20/20, quite a lot see 20/15, and a few see 20/12 or 20/10. An eye doctor should, and typically does, prescribe the refraction for a person's best corrected acuity. To do otherwise would be failing to provide due service. In an eye exam, the whole "which is better, one or two?" Routine stops when one and two are the same.

My understanding is that most healthy adults without any underlying eye condition or health condition that effects their eyes, are able to achieve 20/20 vision with best correction if needed, that lots of people are able to achieve 20/15 under the same conditions, and that some people can even achieve 20/10.

Regarding having 20/20 uncorrected vision, I suppose that there is a difference between someone whose visual system is only capable of seeing 20/20, and somebody who is capable of seeing 20/15 or even 20/10, but is not seeing any better than 20/20 owing to an uncorrected refractive error.

I myself fall into the category. I'm British, so my visual acuity is described in metric. I wear a very small prescription full time owing to eye strain without glasses. My uncorrected vision is 6/6 but I can see 6/5 + 1 (which I understand to be the 6/5 line + 1 letter from the 6/4 line) with best correction, which in my case is:

R +0.50 Sphere -0.50 Cylinder Axis 92

L +0.25 Sphere -0.25 Cylinder Axis 85

In my case therefore, to obtain approximately 20/15 vision rather than 20/20 vision, I need a plus prescription in one meridan.

I suppose however that if a person had no refractive error at all, wearing a prescription of -0.50 would make them slightly long-sighted.

Would this result in slightly better long distance vision at the deficit of slightly worse close vision, or more specifically, would this move the far point of focus further out at the deficit of also moving the near point of focus further out?

Many thanks

Lou


Cactus Jack 09 Sep 2017, 10:53

Stacy,

Those pinhole glasses are pretty much worthless. Sometimes people who need vision correction will notice a difference looking thru a pinhole or button hole. If you don't notice much difference, you probably don't need any correction or very little correction. I don't think there is anything wrong, but there is no way for me to tell from here.

You did't mention your age, but if you have not had an eye exam in a long time, it is not a bad idea. If nothing else, it gives you a baseline.

Very mild refractive errors are very hard for an individual to detect. Some like simple farsightedness (Hyperopia) without Astigmatism can be corrected internally, without your being aware that you are doing it. Nearsightedness( Myopia) and Astigmatism cannot be corrected except by contact lenses or glasses.

Another thing about mild refractive errors is that Vision actually occurs in the brain. The eyes are merely biological cameras. If the eyes are delivering a blurry or distorted image, the brain can correct it, IF it knows what something is supposed to look like. Your brain can even produce images without any input. Ever had a dream?

If you decided to get an eye exam (I think you should) you might want to review "How to Study for an Eye Exam" on the Vision and Spex page. If you want to read it and can't find it, let me know.

C.


Stacy 08 Sep 2017, 19:43

The glasses I got were free, I would not spend my money on those. Why are you reccomending I get my eyes checked? Do you think there is something wrong? Is that why I could not see right thru the pinhole glasses?


Cactus Jack 08 Sep 2017, 16:11

Stacy,

Pinhole glasses, where there is an array of holes (many more than one hole) are really not very useful for vision purposes, but they demonstrate a principle of optics and improve the bank account of the person selling them. Eye Care Professionals sometimes use a single pinhole to see if it is possible to correct a person's vision with glasses. Sometimes it is just not possible. In a pinch, looking thru the holes of a large button can sharpen an image.

A single pinhole acts like a camera lens with a very high "f" stop. I won't go into the technical reasons of what happens optically, but the tiny hole has a VERY broad range of useful focus (photographers call it "Depth of Field", but the downside of using a pinhole is that not much light gets thru the hole.

The pinhole is good for some tests, but it should never be worn for most visually intensive tasks. Never for driving and never in low light conditions where every photon is important.

If you have not had one recently, I urge you to strongly consider an eye exam, even if you think your vision is perfect. The eyes are windows into the body and often other health issues are first detected on an eye exam, when it is usually easy to do something about them.

C.


Stacy 08 Sep 2017, 14:05

Hi, I found a pair of pinhole glasses and I remembered reading about them years ago, so i tried giving them a shot. I am not pleased. It is hard to see with them, not only fo I see the grid, I feel like I see double of everything sometimes, one is darker and clearer and one is like a shadow below the actual image. Why are the glasses not working for me? Is this hiw everyone sees with them? I thoughy they were supposed to make everything clearer, guess not.


Soundmanpt 07 Sep 2017, 09:18

Paul

I get you point but aren't we picking hairs here. All I was suggesting is that someone with 20/20 vision if they were to wear -.50 glasses they are going to see slightly better than they do without glasses and about the same as having 20/15 vision. Yes the sharper someone can see the 20/20 line they in fact may be seeing 20/12 with -.50 glasses. I know for a fact that many doctors will prescribe -.50 glasses with AR coating for people complaining that they have some difficulty seeing to drive after dark event though they have 20/20 vision. The -.50 glasses is just enough to sharpen their vision muc like HD vision.


Paul 06 Sep 2017, 17:38

Soundmanpt, please stop suggesting a person with 20/20 vision c an get 20/15 vision by wearing -0.50 additional correction. It does not work that way. Everyone has some "best corrected visual acuity", at which most people see 20/20, quite a lot see 20/15, and a few see 20/12 or 20/10. An eye doctor should, and typically does, prescribe the refraction for a person's best corrected acuity. To do otherwise would be failing to provide due service. In an eye exam, the whole "which is better, one or two?" Routine stops when one and two are the same.


Cactus Jack 06 Sep 2017, 17:27

Latent Hyperopia and Pseudo Myopia are actually the same thing, involving the Ciliary Muscles and Crystalline Lenses.

If a person is Hyperopic, it can be corrected internally by using the Ciliary Muscles to squeeze the Crystalline Lenses to add some corrective PLUS. If they do that long enough, the Ciliary Muscles will have trouble relaxing fully. The same thing happens if a person focuses close for long periods.

The name used depends pretty much on the underlying refractive error. If a person has a low refractive error, they may appear to be Myopic and need Minus lenses to compensate for the extra Plus produced by the Ciliary Muscles and Crystalline Lenses. If they are actually Hyperopic, within the available Accommodation Range, they may appear to have normal or near normal vision, until they start wearing external Plus correction - for any reason - and the Ciliary Muscles and Crystalline Lenses start to relax.

When the Ciliary Muscles and Crystalline Lenses relax the person will need more external Plus or Less external Minus depending on their actual refractive error.

C.


JC 06 Sep 2017, 16:00

I've been a long term GOCer and love experiencing all different kinds of refractive errors. Today I had a dilated exam for the first time in years, and therefore a sneak peak at presbyopia (I'm 37). I hated it! Wearing contacts I couldn't see anything on the credit card machine to pay, and afterwards at home even using OTC readers I wasn't very happy. This is the first time I didn't enjoy experiencing a visual condition. But I suppose a few years down the road I'll have to get used to it.


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