During this time when ripples of heat can obscure your vision through your car or bike's national cycle windshields, it is really important to be wearing sunglasses while driving or when you're out. You don't need to get those really dark ones that may also affect your reflexes as you drive, but at least wear tinted ones (preferably those purposely made to protect from the glare of the sun) .
Our eyes are actually very sensitive to light. Squinting also invites wrinkles. Spending some time in the bright light outside then going indoors will also tax our eyes all the more as they try to adjust to the difference in lighting. This has even resulted in some people feeling queasy. But ultimately, we must do all we can to take care of our eyes... if they alredy get strained from all the screen time we get, the least we could do is not subject them to harsh light.