Healthy retinas contain a large arrangement of chemical defenses to protect from UV-blue light damage. They carry the names xanthophyll, glutathione peroxidase, melanin, and include the more well known agents lutein, vitamin C, vitamin E, and zeaxanthin. However, these protectors can become weaker with disease, injury, neglect, and age.
Another built-in defense is that our natural lenses take on a yellowish tint as we age, which helps to filter blue light. Unfortunately, after cataract surgery, patients lose that benefit. Recently doctors have recommended a replacement for the damaged lens with an intraocular lens (IOL) that is tinted to block blue light. The patient should be made aware, however, that this procedure will diminish scotopic (night) vision.
Blue light is important in "natural" lighting, and it may also contribute to our psychological health. Research, however, shows that high illumination levels of blue light can be toxic to cellular structures, test animals, and human fetal retinas. The industry has established standards for protecting us from extremely bright light and from UV radiation; and research to understand and block harmful blue light as best as possible is underway.
