• Fede Montagud, editor

    The skin “sees” the sun

    15 Aug

    When we tan, melanocytes (skin cells) produce melanin, a pigment that protects our DNA from the harmful ultraviolet rays of the sun. Scientists have now discovered that the melanocytes also produce a light-sensitive element that accelerates tanning.


    UVB rays increase melanin production within a few days of exposure to the sun. UVA rays, however, trigger this process within minutes. The reason is that UVA rays also cause melanocytes to produce rhodopsin, a light-sensitive molecule found in the retina, which, within 24 hours, multiplies the amount of melanin produced by five. This mechanism is our “emergency” defence system against aggression from the sun.



    New Scientist