HairFactz Definitions
Some words have more than one meaning. Only those meanings relating to this site will be used.
All Definitions
Ultraviolet (UV) Radiation
Ultraviolet radiation or UV radiation is the sun's harmful rays, the "invisible rays" that are part of the energy that comes from the sun. UV radiation is made up of three parts: UVA, UVB, and UVC.
UVA: Originally believed to be harmless but now believed to cause skin damage.
UVB: Causes skin damage, sunburn, and skin cancer.
UVC: None reaches the Earth's surface; it is all absorbed by the ozone layer.
Undulate
Changes in the true diameter along the length of the hair shaft that results in change in the cross-sectional shape. This can give the hair a wavy appearance.