Prescription glasses...eyestrain.

[JeffD 0]

Well I started working in a lab making prescription glasses. As a perk I got a pair of free safetly glasses, and they were ground with no prescription (I have 20/20 vision). But after I wear them for a little while my eyes "hurt." is this normal? It doesn't appear to have any prescription, and it was checked many times throughout the lab making sure its for 20/20 vision.

I guess my question is if anyone has worn a prescription that is just a tad off if it hurt your eyes, or even when you got the correct prescription glasses did they hurt for a little while until you got used to them?

Thanks.

[kris12 0]

This isn't the exactly the same thing, but... I wear prescription glasses. When I wear safety glasses in the lab, even if they are just the plastic ones with absolutely no prescription, my eyes will start to hurt. My eyes just get tired and I have to take the safety glasses off.

I don't know what I am going to do when I am going to have to wear them all the time...

Good luck to you with yours.

kristen
swooo #3 MB #3587 P.M.S. #66
"so let go, jump in...what're you waiting for? it's all right 'cause there's beauty in the breakdown"

[Guest]

Polycarbonate safety glasses drive me nuts. They distort a lot more than they should. Try a different brand, if you can.

mh

.

"The mouse does not know life until it is in the mouth of the cat."

[skydivingchad 0]

All lenses, whether they bend light or not, have an optical center, where the vision is nice and crisp. If you look at a plano (non light bending lens) in glasses, it still has a tilt to it, and a curve, so the optics are best on the center. Now combine that with the polycarbonate material that safety glasses are usually made of. Poly is impact resistant, won't shatter, but it's actually a very slow moving liquid. Basically that means that the optics off optical center typically suck. Some people are very sensitive to this, others never notice the abberations. Those that do notice it tend to get eyestrain, headaches, or changes in visual perception. For folks not used to wearing glasses at all, the safety glasses do have a frame, the frame impedes part of your side vision, even if only a little bit, which challenges the brain's control of how the eyes are lined up and work together, which can also result in a headache.

To solve the problem, get a close fitting safety glass to maximize side vision. Under ANSII codes, you can get safety lenses made of glass or other materials, but they tend to be very thick. It is an option, however.

Also make sure that you get your eyes examined. There are a bazillion folks out there (precise numbers, of course) with 20/20 vision, but they are a little farsighted. So they are using the near vision focus to see far away. Then there's less near vision focus left when actually looking up close. Typically if you are wearing safety glasses, you are doing concentrated close work, which if there's a little uncorrected farsightedness can give a whopper of a headache as well. If you work in the lab making glasses, there's likely a friendly eye doc around who would give you an eye exam. My policy is to do exams for those who work with me for nothing, but that varies from doc to doc.

Jen Galbraith OD, MS (aka Mrs. Chad)

Sometimes you're the windshield, sometimes you're the bug.
Pelt Head #3