Your lacrosse helmet needs to have tilt.

Rules to proper lacrosse tilt

When you put your helmet on you eyes must be looking through the upper most bars of the facemask. You do not want to be looking through any other cross bar.

The visor of your helmet should block out rays of sun; if you prefer it can be partially or completely covering your eyes (which may cause you to move your head upwards to look forward). Although, this can only be a part of your apparel if your tilt is lax god approved.