Hi mate,

Depending on the helmet brand you will find choice of visors. In the best case scenario there are 30% tinted and 50-60% tinted. The latter ones are not road legal in the EU or to be more precise it is fine as long as it is sunny but after sun goes down or in cloudy conditions you might have problems with the law. In some countries it is prohibited no matter what. On the other hand the 30% visor should be fine by law and for riding after dusk while at the same time will offer moderate protection from the sun. And of course you can use sunglasses if you prefer or in combination with the above.
I would suggest to check for sunglasses with plastic lenses for safety.

Hope this helps.

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that is how i feel about my XTR
Mods so far:
Hyperpro front springs; Hyperpro rear shock spring; modified air box; LED tail light; LED indicators + new relay; YZ pegs; Lucas aluminum bar; brisk spark plug; snorkel removed; DNA stage 1; second hand DynoJet O2 mod; crash bars; front and rear steel braided brake lines; soft EBC brake pads; mitas 07 tyres, 2in1 Metal Mule exhaust, Blocked AIS, tall OEM screen, OTR bash plate