: The wavelength of ultraviolet ray is less than the wavelength of visible light. We know that light is the flow of photon particles and its energy equation is , E = hf = hc / λ where , E = photon particle energy h = Planck's constant c = speed of light , f = Frequency and λ = wavelength It is seen that as the wavelength decreases, the power of light increases. The wavelength of ultraviolet ray is less than that of visible light and therefore its power is higher. There are three types of ultraviolet rays ( UV) . UV-A , B and C. All three types of rays have shorter wavelengths than visible light or more energy. So they have more potential to harm our bodies. Since UV-B has shorter wavelengths than UV -A and UV-C has shorter wavelengths than UV -B . UV-C . But we are fortunate that UV-C breaks down the ozone atom and absorbs it due to its high energy as it passes through the ozone layer. So UV -C can no longer come to Earth . In the ozone layer, ozone cannot break down atoms and is released into the earth without being absorbed. It has been found that the reactions of UV-A are usually slow and its effects are also long term , much faster than the reactions of UV-B . For example, after playing football or cricket on a hot summer day, we often see our face turn red. This is especially noticeable in the case of children . UV-B is also responsible for the fact that the skin turns black when exposed to the sun . These are small things but UV rays can do much more harm than good. UV rays are said to be the biggest contributor behind skin cancer. Cataracts have a hand behind them. UV rays also play a role in causing skin wrinkles at a relatively young age.