Snow blindness in humans is due to the

UV-C is almost completely absorbed by Earth’s atmosphere, given that the ozone layer is intact. More UV-B damages reaches the surface of the Earth due to the depletion of stratospheric ozone layer. In human eye, cornea absorbs UV-B radiation, and a high dose of UV-B causes inflammation of cornea, called snow-blindness, cataract, etc. Ozone in the troposphere is ‘bad ozone’ and there is no harm in its depletion.