Is That A Christmas Tree?

Don’t be too glad  if you see a Christmas tree in your Grandma’s eye* . It’s no divine indication that she will attain sainthood. In fact it is an indication of her failing vision.

Medical Science which never fails to wonder us all actually has something called Christmas Tree Cataract in which a Christmas tree with all its ornamentations develops in the eye lens.(See Picture) . Cataract is a disease characterised by the clouding of our eye lens due to various physico-chemical reasons. Christmas tree cataract consists of highly refractile, iridescent¹ multicoloured “needles” crisscrossing the lens fibers of the deep cortex². The colours vary according to the angle of the incident light¹.

The exact nature of how a Christmas tree is formed in the lens is not clear. It was observed³ that Christmas tree cataract crystals are in tubular cavities whose double refraction corresponded…