Question for those who wear eyeglasses.

Keep them on if wearing them. I try to wear my contacts when I know I'll be shooting alot. I also wear sunglasses alot. One pair of prescription, one pair regular for when I wear contacts. Removed when shooting, but if wearing contacts, they help protect my eyes from branches (someone was saying they had to wear glasses to protect their eyes).

Contacts make life easier.

If I'm shooting a day baseball game and it's really bright out I'll wear my prescription sunglasses. The problem with that is my eye is further back from the viewfinder and I can't see the the whole frame on my MKIII or MKIIN as well.

Always on

When the diopter is set at the "neutral" poing (-1 diopter), the virtual distance of the focusing screen is one meter from your eye. For most people, that requires "distance" correction, if correction is necessary.

I'm extremely nearsighted (-8.5 diopter correction) so I have to wear glasses to see clearly anything more than 8 inches from my face, including through the viewfinder. That's been for 40 years of shooting now.

I did wear contacts for a long time, but I found the problem then was that my eyelashes kept depositing oil on the viewfinder eyepiece. I'm not sure whether I was more aggravated by that or by not easily seeing the entire viewfinder with my glasses on.

I'm an old guy, so I'm also presbyopic (farsighted), which means I need bifocals. I do very well with progressive bifocals, so that's okay. I tried bifocal contacts, but I discovered bifocal contacts are for people who want to look good, not for people who want to see well. All the designs tend to obscure sharp vision.

One advantage to being very nearsighted has always been that my close vision is good--I never needed a loupe in my film days, and I don't need one for Live View. I just peek over the top of my glasses.

I can't imagine constantly flipping my glasses on and off for any shooting other than maybe landscapes.

I used to shoot without my glasses, but found that it was hard for me to see what was going on in the game without them. I'd rather have a little discomfort and actually be able to see what's going on outside of the viewfinder.

I will wear my contacts if I am headed to the beach or if I plan on being in the sun a lot.

I try to avoid more sun exposure than I already get(swimmer and lifeguard) and use sunglasses-however you will see crazy things in your view finder if you use polarized sunglasses. The view finder in my 1D mark 2 changes from normal to left half blue tint and right half yellow tint....

Mine are on at all times. I'm too used to wearing them all the time.

I wear both glasses and contacts. I try to always wear my contacts when shooting, but my eyes need to rest from them sometimes. I just did a shoot two days ago with my glasses and it wasn't really an issue. I actually learned to shoot with only glasses because I was just to busy to get to the doc to get a new contact lens prescription and I was out of my previous lenses to use.

I do find it easier to not shoot with glasses, but if the option is glasses or no glasses (without contacts) there would be no possible way to do it. I'm nearly blind without correction.