You can adjust the diopter on the viewfinder to accommodate your eyes with or without glasses..
I have always had issues with SLRs right back to the film camera days, and DSLRs - at least the affordable ones with small APS-C sensors - have been even worse. I have -10 diopter correction in my glasses (varifocals) so there is nothing that can be fitted onto the camera that will help. The diopter adjustment wheel only goes to about 2.5 so it is virtually useless. What is very important is what is termed the "Eye Relief" of view finders - this has something to do with the distance of the eye from the lens of viewfinder, and the magnification. (Google for Eye Relief in DSLRs). It might be that you will prefer an Olympus DSLR because they put the image dat up along the side of the image instead of along the bottom..
But if you do not like DSLR viewfinders then don't despair, because Sony have the Alpha 300 and 350 which has a fast live view facility on a flip out LCD, this is in addition to a mediocre optical viewfinder. It may not have got a wonderful review here, but then the reviewers are not challenged by they eyesight. I think a camera that is comfortable to use cancels out most of those top-end pixel peeping problems.John.Please visit me at:http://www.pbase.com/johnfr/backtothebridgehttp://www.pbase.com/johnfr/digital_dartmoor..
I use a Nikon D200 and Leica M8 without any real problems - though the M8 viewfinder is so large that I have to look around it rather than take it in at once. That won't be a problem with a DSLR - especially Olympus who tend to have narrow viewfinders..
It's more or less essential to use the right eye with the M8 so I have switched to that eye on the Nikon too..
I have noticed my eye proescription has changed in the last few months after 20 years the same, but I doubt photography is the cause..
Try keeping both eyes open. It takes some practice to get good at it but that way your other eye has something to do..
I shoot pistols and have learned to do this and have less eye problems because of it..
You ought to have an eye doc. look at you eyes anyway. A little help now might keep that problem from turning into something big in the future..
I'm gonna have to sell some of this stuff so I can buy more stuff! Mummm, more stuff!..
Actually, Canon's XSi has the live view feature as well. But I've found that adjusting the diaopter helps a great deal.James DeRuvoDigital Camera HQhttp://www.digitalcamera-hq.com..