In NFHS and US Lacrosse, tinted visors are illegal. In case of head injury they want to be able to look at your eyes and evaluate if you need further medical assessment. It boils down to a safety issue. So if you are playing competitively under these governing bodies, get a clear visor! The exact area in the NFHS rule book is in Section 5 Article 3.
If you have issues with sunlight, wear sunglasses under your visor, the visor itself may not be tinted! However if you are playing recreationally, you should be good to go – but always check league rules just to be sure!