What part of UV radiation is most harmful to your eyes?

The most harmful part of UV radiation to your eyes is UVA. UVA rays have a longer wavelength compared to UVB and UVC, and they penetrate the skin more deeply, as well as having the ability to damage connective tissue and DNA. This deep penetration can lead to significant eye issues over time, such as cataracts, macular degeneration, and other eye disorders.

It's important to understand that while UVB rays can also be harmful, primarily to the surface of the skin and can cause sunburn, and UVC rays are generally absorbed by the ozone layer and do not reach the Earth's surface, UVA remains a key concern for eye health because of its prevalence and also because it accounts for about 95% of the UV radiation that reaches us. Visible light, while it can cause discomfort, does not carry the same risk for long-term damage to the eyes as UVA does.