It helps them reduce glare in daylight, and enhances vision at night.

The spelling "squint" is correct (squeezing eyelids together, as to block glare or blur vision).

gets in your eyes and distorts vision, might even destroy your retina

Increased glare from lights, especially oncoming headlights when driving at night.

The glare of the sun caused him to crash the car.

She shot him an angry glare from across the table.

Don't glare at me like that please, it's scary.