If outdoor activity involving swimming or excess sweating is planned, a water-resistant formula should be used. Sunglasses serve an important purpose beyond using them as a fashion accessory and protection against glare and squinting. UV radiation from the sun may damage the cornea, choroid, conjunctiva, lens and retina of the eyes. Chronic exposure to solar UV radiation also is a significant risk factor for development of cataracts. Wearing sunglasses is the best way to prevent ocular phototoxicity.
Sunstroke is life-threatening.