What type and make do you use? How long have you had it.
I have a Shark flip front with built in dark folding visor, I find the flip front excellent when I need a cooler ride. The tinted visor is great and beats wearing sun glasses.
Also have a Shark Raw, excellent for hot weather with plenty of air flow, a great helmet with the only down fall being the chin strap. The strap mounting is too far forward and the strap tends to slip forward.