What usually takes place when you have a vision test? I know they test your vision to see what strength glasses you need. Do they also test for other things like glaucoma, etc.

Thanks in advance.

Yes normally they will test for things like glaucoma, do exam of the eye to see if anything else appears wrong,
They check to see if you need vision correction, and find the correct corrections if you do.

Are you having any specific eye issue.

Yes, they test for glaucoma which usually consists of using a puff of air into each eye. It doesn't hurt, it just feels like someone blowing into your eyes.

Just to add... in some places, you have to request and pay a little extra for such tests... well worth the money.