12.11 Vitamins E, C no help against vision disorder

"In May 2009, a study was published in the journal Opthalmology which broadened the field of eye-friendly foods and nutrients. The following nutritional components were associated with a slowing of the progression of AMD [age-related macular degeneration]:

Vitamins C and E
Zinc
Lutein & Zeaxanthin (antioxidant carotenoids)
DHA & EPA (fatty acids found in fish)"
[quoted from here]

Now a new study, claiming C and E have no protective effect at all, appears in the same journal:

"This latest study is the longest-running one to test vitamin E for eyesight in men, and the first to try out vitamin C alone, said lead researcher William G. Christen, of Brigham and Women's Hospital and Harvard Medical School in Boston. It found no benefits of either vitamin in older men who took supplements for eight years."
[quoted from here]

As usual, the field of epidemiology is full of contradictory results. The latest study recruited 14,000 male physicians, a "well-nourished bunch" as the authors noted. Apparently, no one has the last words yet.

12.10 Rainbow in the eye

Rainbow colors in the tear film indicate that it is rich with lipids that are required to keep the aqueous portion of the tears from evaporating too quickly [Source: TearScience] 

What does this mean? Simple: Presence of the rainbow colors indicates the oily film is preventing water in the tear fluids from escaping into air, so the eyes stay moist. On the other hand, lack of this protection leads to a common form of dry eye.