UVA - Ultraviolet A
This is the sun's strong radiation-filled light rays. Ultraviolet A rays have the longest wavelength and they can penetrate into the hair's deepest inner layer, the cortex. The UVA rays disturb the hair cortex's fiber-like cells that gives the hair its strength and elasticity. It can also damage the color pigments that create natural hair color. The UVA rays can also burn the hair cuticle which is the outer hair layer.
The cuticle contains a web of tiny overlapping scales. When the scales are damaged they can not lay flat and will look lifeless, brittle and dry.
UVA rays can also burn and damage unprotected scalp. It is even possible to burn the part of your hair where scalp is unprotected. UVA rays can damage the skin on the scalp in many ways and activate free radicals which accelerates aging. A severe sunburn on the scalp has even been known to cause some cases of hair loss.
UVB - Ultraviolet B
These are invisible rays that also can penetrate deep into the hair's cortex or center damaging the hair fibers. It can also damage the hair cuticle. UVB rays can easily dry out the hair and cause natural and chemical colors to fade.
UVC - Ultraviolet C
These rays are the most damaging but do not reach us because of the ozone layer which currently protects us.
DEEP CONDTIONERS CAN PROTECT YOUR HAIR FROM HEAT DAMAGE CAUSE FROM THE SUN. USING HAIR PRODUCTS THAT CONTAIN A SPF BETWEEN 8 AND 10 WILL ALSO HELP TO PROTECT YOUR FROM THE RAYS OF THE SUN. PLEASE READ THE BACK OF THE PRODUCT TO MAKE SURE IT CONTAINS (Octyl Methyosycinnamate Octyl Methyoxycinnamate i, ).LEAVE IN CONDITIONERS CAN HELP ALSO BUT DONT LAST AS LONG. AFRICAN SHEA BUTTER IS ALSO A GREAT PRODUCT FOR HAIR SUNBLOCK .