Wally world and other stores exam typically are just a refraction they really do not check your eye health early detection of some eye problems is the difference between seeing and not. my wife is in the business and I have gone to both I will pay for a full exam where they dilate and retina scope. Walmarts Labs are in Mexico and if you get there lens compared to other lenses available there is a huge difference in clarity I have had both. I appreciate my sight and comfort of my glasses I will not scimp. When you go to the dentist do you ask for cheaper fillings.