Yes the Walmart Vision Centers does do eye exams.
You can purchase the eyeglasses when you're prescribed the eyeglasses and they will examine your eyes to see whether or not you need eyeglasses.
A regular eye exam is around $80.00 and a contact lens eye exam is around $130.00
Then there's the cost of eyeglasses or the contact lenses if you need them after the eye exam.
So far I don't need eyeglasses or contact lenses but every few years I will go to Walmart Vision Center and get a cheap eye exam to find out how my eyes are.
I find it cheaper to pay for an eye exam at Walmart Vision Center than going to a regular eye doctor.