Why can't I see clearly through eyeglasses?

January 24, 2011 9:54 AM

Why can't I see clearly through eyeglasses?

I usually wear contact lenses, but I would like to be able to switch to eyeglasses on occasion. But for years now I haven't been able to get a pair that I can see through. It's always the same problem: If I look straight through the center of the lens, I see fine. But the more I look off-center, the more blurry things are. It's headache-inducing and makes them useless. Every couple of years I try again, and the same thing happens, and the opticians I've used haven't been able to provide an answer. I suspect it's something to do with the high-index lenses, as I don't remember this problem when I was younger and used the old-fashioned lenses. Yet my google skills are failing to find any reported problems of this type. I'm nearsighted, -6.75 and -7.25, with a slight astigmatism. What I'm looking for is an explanation for why I can't wear lenses that seem to work fine for everyone else. I've had this problem with four pairs of glasses in a row, made over a period of five years from different companies in different states.

Does anyone know what might be causing this?

posted by Pater Aletheias to science & nature (11 answers total)

Are you expecting peripheral vision? That won't happen with glasses. That's one of the benefits of contacts.
posted by litnerd at 9:56 AM on January 24, 2011 [1 favorite]

How long have you worn the glasses before giving up? Any time I switch to a new pair of glasses it can take awhile -- maybe a week -- to adjust. During the adjustment period I'll often feel a little disoriented or headachey, but it goes away. Different types of frames will give you different amounts of peripheral vision.
posted by Anatoly Pisarenko at 9:58 AM on January 24, 2011 [3 favorites]

I just got a stronger prescription—similar to yours, if not worse—and I'm having the exact same problem. I still wear my old glasses because it's so annoying. Just keep at it for at least a day...and if it doesn't improve, complain to your eye doctor.
posted by lhude sing cuccu at 10:02 AM on January 24, 2011

Just another data point, I'm -8.5 or so with slight astimatism, no dominant eye and wear high index lenses. I wore contacts for years, but I can't be bothered with them any more so I wear glasses daily. I see fine looking straight ahead and out of the sides of the lenses, though there is some distortion (not fuzziness) as I get really really close to the frame.

Of course, I cannot see clearly outside the frames. The lenses aren't there.

On a hunch, what happens if you push your glasses all the way up your nose and hold them there and then look towards the edges of the lenses?
posted by Brian Puccio at 10:09 AM on January 24, 2011

You could ask your optometrist to check for convergence problems. Convergence issues are common enough---your eyes may not track perfectly away from the centre of vision. The way normal glasses are ground assume that eye tracking is perfect, that both the left and right eyes are perfectly coordinated.

the good news is that many, mild convergence problems can be corrected with "prisim" lenses. An optometrist, or perhaps better an ophthalmologist, can figure it out for you.

I have mild disconvergence from some old surgery. For me, I just adapted to it. Yours, if that is your problem, sounds a bit more severe.
posted by bonehead at 10:13 AM on January 24, 2011 [2 favorites]

Do you have a different prescription for glasses than you do for contacts? Are you getting your prescription from an optician or an optometrist? Go to an optometrist (a good one) to get two separate prescriptions for glasses and for contacts.
posted by pised at 10:22 AM on January 24, 2011

That's just the way glasses work, particularly at higher prescriptions. Your prescription will NOT be in sharp focus off center; there is too much curvature in the lens to make the center sharp AND the sides sharp. In a lower-index lens, the lens is "flatter" and more of the lens is, in effect, giving you the desired prescription.

The solution I've found is to wear the glasses non-stop for a week or two, and then regularly wear them (if you're switching back and forth with contacts). I've gone through this several times with my glasses--each time I change the frame, something is subtly different, and it drives me absolutely crazy for a couple of weeks, and then my eyes get used to it.

Of course, I am not an optician or ophthalmologist; consult your eye care provider with your concerns...
posted by Admiral Haddock at 10:22 AM on January 24, 2011

I had that problem (and about the same prescription as you, just a little weaker.) I could only stand to look through the glasses right in the center. Anything off center looked weird and prism-y (?) If I looked at something bright there was a blue line on one side and a red line on the other. I don't know how to explain it. Also, my depth perception was very off, like I was drunk. My hands would look veeeery far away and skinny if I held them out in front of me. My doctor said that it was my astigmatism and reduced the astigmatism correction a bit. That helped enough that the glasses were bearable. I had Gas Permeable lenses for years and years and he said that they corrected my eyes so well that I'd never be as happy with glasses as with the gas permeables. (If you have regular soft contacts, those worked for me, just not as well as the gas perm ones. They moved around more and my vision wasn't quite as sharp. I had to wear those for a couple of months and then glasses for a couple of weeks in order to get LASIK. Never got used to the glasses entirely even with a mandatory two weeks of wearing them. Also, the lack of peripheral vision was annoying. Love my LASIK eyes, though.)
posted by artychoke at 10:37 AM on January 24, 2011

In my experience all high-index lenses are painful and useless the first week. After that, it's time to go back to your optometrist.
posted by SMPA at 10:41 AM on January 24, 2011

You may be experiencing spectacle blur--contacts slightly alter the shape of the cornea, which needs some time to bounce back after you remove them. I need at least an hour between wearing contacts or wearing glasses, or I can't see out of the latter. (Which is awkward, because my vision is much worse than yours...)

However, even once the blurring effect has worn off, things are still not great at the peripheries; as others have said above, that's standard for glasses.
posted by thomas j wise at 12:02 PM on January 24, 2011

I recently got new glasses with HD lenses and love them. They expand the area that remains in focus when you move your eyes, so there's less head turning.
posted by Short Attention Sp at 4:51 AM on January 25, 2011