Eye tests

Factual Questions
1

So I have just gone to get my eyes tested. At both places, they gave me an electronic test with that big machine that you stare into (at a picture of a house or road or something). They also both gave me the more traditional eye test with letters on the wall whilst trying out different lenses.

These are both highly respected chains. These are my results for Optician A:

(Left eye, Right Eye)

SPH -0.75, -0.5
CYL 0, -0.25
AXIS 170 degrees, 180 degrees

Optician B:

SPH -0.25, -0.5
CYL 0.5, 0
Axis, 180 degrees, 0 degrees

ie the results are almost completely conflicting. I originally guessed that one of them had filled out the form wrong by putting the results in for the left eye into the right eye box (and vice versa). However, on closer inspection, this could not be the case as the numbers are actually different anyway.

Anyway, I’m 25 and I’ve never worn glasses or felt the need to. With both of my eyes open, I have never strained to read, watch TV, drive etc. If I shut one eye at a time, I find that objects at a distance are blurry.

My question is, how accurate are these eye tests and do I really need glasses? One of the opticians told me that if I didn’t wear glasses, that my eyes might get worse. I have also heard the exact opposite before (ie if you do wear glasses when you don’t REALLY need to, then your eyesight will get worse).

My suspicion is that a high street optician wants you to buy glasses from their shop, and will be more inclined to say that they are necessary. However, I would appreciate the Straight Dope on the matter as this is highly perplexing issue. :confused: Apart from anything else, I don’t particularly want to have to spend $200 on lenses and frames.

2

Okay so now I have been for a THIRD test and got completely different results AGAIN. This cannot be right.

The optometrist was desperately trying to convince me that I need glasses (from his shop). I am convinced that this is a scam. Can somebody please enlighten me?

3

Your prescriptions are miniscule, and the differences are too – they are far from “totally conflicting.” If you are not having any difficulty seeing, then don’t wear glasses. You cannot harm your vision either way.

4

That’s what I thought but the last guy I went to see was utterly convinced that, if I didn’t wear glasses, my eyes would get worse. He said something about my right eye becoming lazy blah blah.

Is it all really a way of persuading you to spend a fortune on the frames that they have sitting downstairs or is there ANY truth behind what these guys are saying?

5

I went to an eye test (my first one at 25) at a local walmart which DO NOT sell glasses. His office just happened to be there.

Anyways, I have -2.75 in my left eye and good vision in my right eye (well, I think he put down +0.25). He said I didn’t need glasses and this sort of thing was actually good for me. Since my “good” eye could see far away things while my “bad” eye would be able to read close objects.

He gave me a perscription but said to keep it unless I felt like wearing glasses. He said it wouldn’t affect me either way if I wore glasses or not (my vision would not get worse over wearing/not wearing glasses).

I got glasses anyhow (through my insurance) and my glasses make me dizzy so I never wear them.

I wouldn’t worry. I would try to find a doctor who doesn’t sell anything and get tested only at those types of places.

6

Why don’t you get your eyesight tested by an actual ophtalmologist, and ask him whether or not you actually need glasses, rather than by an optician whose interest is to sell you glasses?

7

He’s right and you’re lucky. With your left eye, you will be able to read and see close objects well once presbyopia develops (which, in your case, will be another 15 years), and with your right eye you can see distance. Your brain adjusts, especially since this has been the condition since childhood.

Vision varies throughout the day, and the corrections noted in the OP are within the realm of normal variation. With the right eye needing a correction of only -.5 and little or no astigmatism, I, if I were you, would not wear glasses. Your left eye appears to be approximately the same. With the very slight myopia, you will be able to postpone wearing reading glasses until you are over 50, or so.

Eyestrain may be harmful to one’s eyes, but only at an early age. At age 25, this is not an issue, and with your vision, you are not straining your eyes to see well.

IANAED (eye doctor). BTW, an optometrist is well-qualified to test your vision. You do not have to see an opthalmologist, who probably would just have one of his optometrists test your eyes anyway.

8

Just a clarification.
Opthalmologists deal more with diseases of the eye.
Optometrists deal with visual problems.
Opticians make glasses. There are some areas of overlap.

Optometrists do check for glacoma and cataracts, but they refer to opthalmologists for treatment.
Optometrists have the most education in testing vision. (6 years, I believe.) Opthalmologists cover vision testing during their 3 year fellowship, after medical school. Its just a small part of that post graduate education.

Did any of your examiners mention astigmatism? If present, it can make vision testing inconsistent and difficult.

9

I’ve always thought that the cylinder + axis is the correction for astigmatism.

10

The reason it complicates the exam, is that the cornea is, for want of a better term, “lumpy” a little like looking through very old glass, with an inconsistant surface. If the examination environment is slightly different, the light may enter through a “lump” or not.

I don’t think I’m explaining it all that well, sorry.

11

OK, then my comment wasn’t helpful. Here, only ophtalmologists deal with visual problems/ diseases of any kind. I don’t think there’s such a thing as an optometrist. I uncorrectly assumed it was the same in the US.

Still, I wouldn’t rely on someone who makes his living selling glasses to tell me whether or not I need them. And the OP was advised by two opticians, and then by an optometrist who also sell glasses. Do all optometrists sell them? If not, why not have an eyesight test done by one who doesn’t sell glasses? Or in an hospital, for instance?

12

I would not get my eyes checked by someone who sells glasses either. There is simply too much conflict of interest. Not all optometrists sell them. Mine certainly does not.

There is still the problem of finding an optometrist who is truly a master. This can be very difficult, and most people don’t know how to tell. I don’t either. I just go to the same guy I’ve always gone to (an hour from my parents’ house, so I only see him when I’m visiting them.) My mother knows a lot more about this than I do because she works with kids who have learning problems–mostly due to vision problems that were never caught–and I trust her judgement.

It’s also very difficult to get your glasses made to exact specifications. There are certain “acceptable” margins or error for lenses that the better sellers of lenses will scoff at. This is particularly a problem if you need something weird like prismatic corrections. Your local supermarket or Lenscrafters may not cut it. Heck, the places I’ve tried in El Paso couldn’t even get the polarization in my sunglasses lined up correctly.

And of course, YMMV.

13

Do you really need glasses? Well, I think you’d probably be surprised at the difference glasses can make, even with such a teensy prescription as you have. Even small changes in my prescription make a huge difference in what I can see when I get new lenses. Are your eyes going to rot out of your head leaving you permanently blind if you do or don’t get glasses? Well, no. Your vision gets worse because of changes inside the eye, and a pane of glass in front of the eye isn’t going to cause or prevent those changes.

Most optometrists will recommend that anyone with slight vision defects such as yours get glasses and wear them as needed. This isn’t because they’re out to rip you off, but because it’s their professional duty to make recommendations to help you optimize your vision and improve your quality of life. You can get the glasses or not (most optometrists don’t actually sell glasses, but many have their offices right next to opticians to increase traffic, so they generally don’t make any money off your lenses), but they have to make the recommendation. It’s like my doctor suggesting that I take prenatal vitamins when I started taking Depakote. She wasn’t making any money off the vitamins; she made the recommendation because she felt it was in my best interests.

14

I don’t know about “most optometrists.” I know an opthalmologist who has an optician on the same floor, right next door, to his office. But my optometrist sells glasses. He doesn’t make them, of course, but the lenses are made to his specifications, and he has a wide range of frames to choose from. In addition, you can get transition, no-line bifocals, etc. ordered through him. And his mark-up is quite high. I happen to know a lady who works for him (I used to run with her) and I complained once of the high prices he has for his frames. She said that she once talked to him about that, but that’s the way he prices them, even though some frames have not sold in years.