I think it'll largely depend on how bad it is per individual, but in my case, (one eye is perfectly fine the other was already so bad that corneal cross linking* wouldn't be helpful) it's pretty bad, I guess to give an idea, imagine playing VR with one eye uncovered, but the other with 2-3 copies of the image trying to fight for focus.

Life itself is fine, since the optic nerve is pretty amazing, unless I close my good eye, I don't even really notice it. But for some reason this just doesn't quite translate over into VR.

*Basically scratching a grid pattern into your cornea then flooding everything with vitamin B and UV - the idea being that it forms a strong matrix that resists the changes to cornea shape.