Solar viewer

Solar eclipse glasses.
The solar eclipse of December 26, 2019 seen through a pair of solar eclipse glasses in Jaffna, Sri Lanka.
A cat demonstrating a pair of eclipse glasses.

Solar viewers (also known as solar viewing glasses or solar eclipse glasses) are special eyewear designed for direct viewing of the Sun. Standard sunglasses are unable to filter out eye-damaging radiation. Solar viewers can be used for safe viewing of solar events such as eclipses. The recommended optical density of this eyewear is 5, meaning that the solar viewing filter only permits 1 part in 100,000 of incident light to pass through. In addition to blocking visible light, solar viewers also block ultraviolet and infrared rays which can damage one's eyes.