My DD2 got her glasses at 6yrs. She was SO upset and hated them. No issues though with other kids at all. The school wouldn't have allowed it anyway. Its not like it used to be when we were in school.
She wore them but not as much as she should have and in the end at her check up the following year they needed to be a bit stronger again. We were told that if she does wear them then there is a chance that her eyes will correct themselves over time and she might not need them later on. So, we have focused on that.
She actually did realise she could see well with them on though. She was torn between thinking oooooh I can see and not wanting to wear them.