I'm not a huge fan of wearing safety glasses while rec climbing. My face gets sweaty, and I don't wear vision glasses in regular life, so I find it distracting to have that shield in front of my eyes, blah-blah-blah.
However...
I was climbing a redwood a few months ago, and I got some fluffy bark duff kicked in my face. My eyes watered and I had to stop and blink a lot while they watered, but I seemed to recover and get on with it. A few days later, my eyelid swelled up, and stayed that way for six weeks. I did warm compresses 3-6 times a night, but it didn't change or go away. Then it got infected. I finally went to the ophthalmologist, and you do NOT want me to describe what they did to me. It was a mix between the eyeball scene in A Clockwork Orange plus the eyelid-cutting scene in Rocky, followed by a few days where I looked like I had been in Fight Club. I just went for a follow up with an optometrist, and by using glowing dye, they said I also scratched the lens in that eye.
My point is this. I'm feeling a lot more open to wearing eye protection while climbing now.