Same here in US, but you won't get an infraction, if it's prescribed by doctors.
All you do is, go see doctors 'n tell them that you need your windshield tinted b/c you're vulnerable to brightness / sunlight / UV, etc. They'll give you a written statement, and you keep that in your glove box in case you get pulled over.
Over here they would send you off to have your eyes tested and give you glasses lol