Eye tests

Thoie

Just a notion, but someone here might be able to explain to me if/why I'm wrong.

When you go to get your eyes tested, you're often shown a bunch of letters projected on a screen at a set distance. Then the optician swaps in and out lenses to see which ones are better/worse. To me this seems like a hangover from the old days when the letters were on a sheet of paper. The "lens swapping" machines are much fancier than they used be, but I wonder if they've upgraded the wrong part.

Would it work if you gave each patient a dial (linked to the projector), and they adjusted this dial themselves for each eye until everything was crystal clear? Then a reading could be taken from *waves hands* somewhere which would indicate the prescription for each eye?

For those interested in my thought processes, an acquaintance and I were using a projector yesterday. Neither of us wear glasses, but I suspect maybe one of us should Everytime he adjusted the focus, I felt that he was bypassing the "good" spot, and taking it just a teensy bit off what was right (to my eyes). We were both standing the same distance away from the screen.

sam34

i think the current "which is clearer lens 1 or lens 2?" way can be a bit inaccurate. sometimes ive clearly said to opticians that i can see no difference btwn the two, and they say "ok i'll show you them again" and then press me to pick one, even though i already said i could see no difference.

i always feel under pressure having my eyes tested and i am never completely happy with the end result.

there has to be a more scientific way of doing this? i dunno, maybe they could measure the whole eye and the size and shape of the lens or something.

benj

i also feel under pressure with eye tests to pick "better" OR "worse"
in the end i just pick one but never know if it's the right one...
it would be great if we got a new eye test system.

DrIndy

I think its to check for rotation or astigmatism which is the distortion of your cornea rather than the overall shape which causes short-sightedness or long sightedness.

If you have no astigmatism then both should be the same - but the optician knows what lenses were put in so you should probably see something different.

sam34

it just seems very subjective. i always suffer from performance anxiety in there and end up giving a definite answer even if im not really sure.

i hate having my eyes tested, i absolutely dread it.

Thoie

sam34 wrote: »

i always feel under pressure having my eyes tested and i am never completely happy with the end result.

there has to be a more scientific way of doing this? i dunno, maybe they could measure the whole eye and the size and shape of the lens or something.

Not being male, I feel less pressure in that regard and will happily admit that I can't see any difference

I think that measuring the eye itself might not be a whole amount of use as various other things come in to play like the optic nerve and brain receptors, but if anyone with actual biology knowledge can tell us different that would be great.

benj wrote: »

in the end i just pick one but never know if it's the right one...
it would be great if we got a new eye test system.

This is where I feel if the patient was controlling the dial (would probably only work for adults, or older kids), they'd be able to tweak the view as they liked for the best clarity. It's the same way that no-one else can ever adjust your pillow for you just right. This dial would obviously have a "reset" button to bring it back to 0 for the next customer, and would need calibration checks.

There must be some reason why we stick with the old way though, and I'd love to know what it is.

sam34

Thoie wrote: »

Not being male, I feel less pressure in that regard and will happily admit that I can't see any difference
QUOTE]

i'm not male either!! but i still do get the ol' performance anxiety when in teh opticians chair

tallaght01

I was at an opthalmologist once. He got me to look through these binoculars, at a picture that was inside them. The pic gradually comes into focus for you, and the majik binocular machine prints out a piece of paper telling you what glasses you need. I didn't need any.

Anyone ever seen that before? I've no idea what it was. This was a super posh private clinic, though.

sam34

tallaght01 wrote: »

This was a super posh private clinic, though.

should have gone to specsavers