Quality-wise these goggles  are indistinguishable from the very best prescription goggles I have used in the past. They are optically perfect, well made, durable and best of all, dirt cheap!
I have been using them for years, if there is a minor criticism is for the anti-fog coating on the inside of the lens. The coating is not very durable, when cleaning, the lenses need to be handled with great care.

Pros:  The headband is one of my favorites--it doesn't catch in my hair or cut into my skin.
Cons:  1) The bridge digs into my nose slightly, no matter which of the three bridges I use.  2) I made the mistake of wiping droplets from the inside of the lenses with a cotton towel which permanently smeared the anti-fog coating--I had to use goo remover to get rid of the rest of it so I could see again, but they now fog up.  3) The seal appears to degrade with time because they leak more than they did when they were new (one year ago).

Very good product, great bargain, optical quality perfect.
A few complaints though:
Head-strap material very durable but slippery, tends to loosen up,  
requires frequent adjustment.
Anti fog coating not as durable as would be desirable.
All in all, among the best goggles I ever used.

These goggles are great because they correct my eyesight so I can recognize my friends in the pool.  Sometimes I have trouble with the seal and have to adjust them.  I have that problem with most goggles though. The straps don't slip out of place so I don't have to spend time rethreading them.  I like it that there are two straps in the back to help me keep the goggles on over my swim cap.  So far the antifog treament that they come with is still working.

I use these in an indoor pool, they work as well as the more expensive ones

My son's prescription is high for someone so young.  He was THRILLED to know there was sauch a thing as prescription goggles and I was THRILLED with the price!  The best part is the antifog feature.  I wish mine were antifog!