I've been using them for a year.
They really protect the lens of the phone,
and when they break, they change very easily just by using a card

The photo is hardly distorted at all and there is nothing better on the market than this product

It is not useful if you buy a case. If you have your phone without a case, it might be more useful, but for me, when I had to remove the case, the protective cover of the cameras came off as well.