Is it necessary for pilots to wear sunglasses while flying?

[Junction]

I just found almost every pilot would wear sunglasses while flying. Is it necessary for them to wear sunglasses?

[Junction City]

Yes. Sunglasses are necessary for pilots when flying. The UV rays are so strong because the thin athmosphere doesn't work too well in filtering the UV rays. So pilots should wear sunglasses when flying to protect their eyes from harmful UV rays in case their eyes get damaged by the strong sunlight and UV rays. Besides sunglasses can help them adapt to darkness more quickly when they fly at night. However, pilots shouldn't wear polarized sunglasses because the windshields of the airplane is polarized, which would interfere with the polarization of sunglasses.

[Juneau]

I don't think it is necessary. Some pilots don't wear it. Of course, there are some pilots do wear sunglasses during the day. Sometimes even on the ground. Anyway,Sunglasses are not worn to be cool, sunglasses are also worn for shield eyes from extremely bright sunlight at altitude, thus to reduce the rate of things like macular degeneration later in life. So, it is a wise choices of wearing sunglasses while flying.