The Great Outdoors Stack Exchange is a question and answer site for people who love being outdoors enjoying nature and wilderness, and learning about the required skills and equipment. It only takes a minute to sign up.
Sign up to join this community
In addition to sunglasses, you can get clear safety glasses that claim "Blocks 99.9% of harmful UV rays". The advantage of clear safety glasses is that they can be worn both during dusk and after dark when there are millions of tiny bugs trying to fly into your eyes.
It made me wonder how essential is the darkness/tint of a pair of regular sunglasses, and how good clear safety glasses are at protecting your eyes from the sun?
The dark tint isn't required for UV blocking. That's not to say it's not a good thing to have.
Many plastics have strong UV absorption, and some safety glasses have an additional coating. For blocking UV lasers this has been tested, though UV laser glasses are often a pale straw colour. Many safety glasses actually have UV protection anyway.
There are also UV-blocking clear glasses designed for their anti-UV properties above other functions.
Of course, the visible component of light that also contains a lot of UV is often intense enough to be uncomfortable, and to cause eye strain. This is a good reason for sunglasses to be dark. For cycling in particular I use safety sunglasses, which are a good combination of mechanical/dust protection and light blocking (visible and UV).
Blocking UV and reducing visible light intensity are separate functions, and the latter can actually reduce the former; glasses that are opaque to UV but completely transparent to visible light will mean that pupils will be constricted in direct sunlight, reducing UV exposure.
