According to the U.S. Food and Drug Administration (FDA), many factors determine the amount of UV exposure including:
- Geography- UV rays are strongest in areas close to the equator.
- Altitude- Higher altitudes have greater UV exposure because there is less atmosphere to absorb UV rays.
- Time of year- The sun’s angle in relation to the Earth varies according to season. During the summer months the sun’s rays hit the earth at a steeper angle, resulting in a greater amount of UV radiation.
- Time of day- UV is most intense at noon when the sun is at its highest point in the sky. Especially in the summer months, it is a good idea to remain indoors during the peak sun hours of 10am to 4pm.
- Weather conditions- Even under cloud cover it is possible to damage your skin and eyes, and cause long-term damage.
- Reflection- Surfaces such as snow, sand, pavement, grass, or water can reflect much of the UV radiation that reaches them.
Wearing UV-blocking sunglasses with a brimmed hat is the best protection against UV rays. Prevent Blindness recommends choosing sunglasses for children, adults and senior citizens that:
- reduce glare
- filter out 99-100% of UV rays
- are comfortable to wear
- do not distort colors
Information courtesy of Prevent Blindness