I think professional tennis players shouldn't wear sunglasses when playing tennis. I could never wear sunglasses when playing tennis because they always affect my vision so that I can't see the ball clearly. The rims of the sunglasses blocked my vision when I hit the ball. And I've never seen professional tennis players wear sunglasses when playing tennis.
They shouldn't. The problem is that the sunglasses make it harder to see the ball because everything is dark. So professional tennis playes won't wear sunglasses when they play tennis. Otherwise the sunglasses will affect their sight.
If you wear sunglasses when playing tennis, the lens of the sunglasses will make everthing darker abd the frame will affect the peripheral vision, so you can't play well during the game. What's more, the sweat can quickly make the lenses fog up and then mess up your vision. So professional tennis players shouldn't wear sunglasses when playing tennis.
Professional players would think it impares their vision. But a lot of amatures wear them. It's just a matter of getting used to them. I like them because your opponents can't see where you are looking. Especially in doubles.