Just a bit short of x-ray vision...

November 2, 2007 9:34 AM

Did my optometrist give me semi-superhero vision?

I recently went in for an eye exam, current glasses are 3+ years old. My optometrist told me that my prescription has barely changed, and in some tests told me that I have 20/15 vision.

However, when I went to pick up my new glasses, everything was extremely sharp, even from long distances. The first thing I noticed was the texture of optometrists skin , then looking in the mirror at my face noticed all sorts of things that I'd never noticed before. (I guess my skin isn't as good as I thought)

Its like the sharpness knob got turned to 11, everything is crystal clear. Lighted signs at night are especially beautiful, and when I arrived home, I almost got a sensory overload seeing how pretty the carpet fibers looked.

Whats going on? Did my all previous optometrists give me regular 20/20 glasses and this one gave me 20/15? (does that make sense? or is even possible?). I was expecting to get a headache from the new prescription, but no issues over from last night and this morning.

posted by mphuie to health & fitness (12 answers total)

Isn't it great? I had a similar experience with my new OD. During the course of the examination, I mentioned my old eye doctor (MD). He said, "Oh, I could tell from your prescription. MDs usually correct in favor of [long eye condition name]. Let's see if you like my way better."

So the difference in treatment between an MD specializing in the eye and an OD could account for your new vision.
posted by infinitewindow at 9:45 AM on November 2, 2007

This happens to me every time I get a new pair of glasses. Sometimes my prescription changes and sometimes it doesnt. I imagine its mostly psychological. After a while we get used to the new lenses and things feel normal. Or there's something to be said about the composition of the lenses and how looking through a completely different piece of plastic cant be 100% the same as the old piece of plastic.
posted by damn dirty ape at 9:46 AM on November 2, 2007

Since your old glasses are over three years old, they probably had some wear on them that led to decreased sharpness. I had glasses 5 years old and finally gave up and got new ones not because my eyesight got worse, but because the various scratches and scuffs had merged to pretty much cover the entire surface. The new glasses gave me back the sharp details much as you describe (especially in the case of lighted signs, as you mention).
posted by mikepop at 9:47 AM on November 2, 2007

IANAeyedoctor, but I'm betting it's the newness and quality of the lenses more than the prescription.
posted by FelliniBlank at 9:47 AM on November 2, 2007

Aside: Yes, 20/15 is perfectly possible. It basically means that you can see at 15 yards what the average person can see at 20 yards. (I think it's yards...) 20/20, despite what people think, isn't perfect vision: it's average (good) vision.

It leads me into the bizarre trap of thinking, "I wonder how good it can get." Can I have 20/5? 20/1? 20/0.05?
posted by fogster at 9:58 AM on November 2, 2007

And... I said it backwards. :-[ You can see at 20 what the average person can see at 15.
posted by fogster at 9:59 AM on November 2, 2007

I'm not so sure its the old lenses, because my backup pair looks about the same as my previous lenses, just not as yellow.

It might be the lens quality? Maybe marked improvment in manufacturing? I got my new ones at Costco, and my old ones in Hong Kong.
posted by mphuie at 10:06 AM on November 2, 2007

I had an optometrist once tell me that he likes to write prescriptions one step sharper than what people actually need, as most people really like the perceptual effect. He even demonstrated on the Omnispectacle thingy: here is what your eyes require as measured, and here's one step sharper. I immediately preferred the extra-sharp prescription. Maybe that's what's going on here.
posted by ulotrichous at 10:22 AM on November 2, 2007

You probably got a better presciption measurement this time. It's happened to me too: go to an optometrist, get a semi-ok prescription, go to my opthomologist, get a crystal clear one.

Either that, or you've worn out your old glasses by looking through them too hard.
posted by bonehead at 10:55 AM on November 2, 2007 [2 favorites]

It could be a difference of the lab used. Some labs are very particular about the "grind" of the lense. Someplaces (Lenscrafters, etc.) have a wider range of what is actually acceptable.

It could be this added to the new prescription made a huge impact.
posted by 6:1 at 11:12 AM on November 2, 2007

If you're young and your cornea, lens and vitreous are clear and without aspherical aberration, you may be able to do better than 20/20. There is an element of chance involved; both contacts and glass lenses try to approximate the correction necessary to your individual eye with one spherical and zero or one cylindrical corrections. If that happens to produce an excellent fit for your eye and your eye is otherwise perfectly healthy, you can sometimes get vision as good as 20/10.

When I was younger I came away from the optometrist a couple of times with at least one eye 20/15. This always disappeared within a couple of weeks, almost as if there was some regulating or feedback process causing my eye to react to such good vision by defocusing slightly. I am ignorant about what process, if any, might have accounted for that.
posted by ikkyu2 at 1:17 PM on November 2, 2007 [1 favorite]

I've often wondered what the world record for unaided visual acuity is, by the way. I've not been able to find any systematic tracking or study of this - Guinness doesn't keep track of it.
posted by ikkyu2 at 1:23 PM on November 2, 2007