Apoptosis is a physiological process, that promotes the active suicide of cells, resulting in an advantage, unlike necrosis which occurs from trauma.
While UV light is essential to human life it can also cause harm by inducing cancer, immunosuppression, photoaging, inflammation, and cell death.
Once the keratinocytes have been damaged irreparably as a result of UVB radiation, they are marked for destruction by apoptosis to eliminate them as they are potentially mutagenic cells.
This phenomenon was demonstrated in tears, which have higher levels of potassium ions, and bathe cells of the eye and therefore provides protection from UVB radiation.
[6] A study reported in the International Journal of Molecular Sciences in 2012; 13(3), pages 2560-2675, published February 28, 2012 by Terrerence J. Piva, Catherine M. Davern, Paula M. Hall, Clay M. Winterford and Kay A.O.
It was reported in that study that the process of apoptosis includes: "detachment from the substrate, followed by loss of specialized membrane structures such as microvilli.
[8] Since apoptosis is a last resort alternative, it takes the initiation of multiple other genes (ING2, p53, or Ras subfamily) expressed before the cell is finally programmed for death.