Blue Light and Macular Degeneration

[Chris Ryser]

Blue Light and Macular Degeneration

Interesting article on the web:

In many primate studies, blue light has been shown to cause a photochemical reaction that produces free radicals in the RPE and the rods and cones. Researchers believe that these free radicals interact with the high oxygen and lipid content in human rod and cone tips to produce abnormal chunks of metabolized waste that cannot be properly processed by the RPE, clogging up the macula's maintenance system and producing dry macular degeneration.

Melanin, the substance that gives eyes their color, protects the macula by trapping light rays so they don't reach the macula and cause damage. People with fair skin and blue or light-colored eyes may be particularly susceptible to macular damage by blue light because they have less melanin in their irises. Their blue eyes transmit up to one hundred times as much light to the back of the eye as dark colored eyes do. Additionally, when the light reaches the choroid and RPE of people with fair skin and blue eyes, there is less melanin there to absorb the radiant energy, leaving these tissues more vulnerable to light damage. Can blue light rays cause macular degeneration? Can you reduce your risk by protecting your eyes from blue light? The answer is maybe.............................

continue reading: http://www.mdsupport.org/library/blulight.html

[Ginster]

Great article Chris, thanks for posting it.:)

[finefocus]

"Blue blockers do not act like regular sunglasses. They appear tinted, but they do not reduce overall light or make the world look darker. They alter the appearance of blue and green colors and reduce glare, but they don't affect the way other colors appear. In fact, they may even improve color contrast. Because of these characteristics, blue blockers were very popular a few years ago as sports glasses. Many people with macular degeneration find them particularly helpful regardless of their health benefits, because they reduce glare indoors and outdoors while keeping the world bright and visible."

OK, I don't get it. They "appear" dark but don't darken: filter selectively and "improve color contrast", yet don't affect the accuracy of color vision. They are apparently OK for night use, although a thread last week clearly concluded that any tint was too much at night (while driving, at least). Also, why would yellow, or brown, or plum, filter blue light better than gray? Sure, gray will seem darker, cooler, because it will also filter the rest of the spectrum, but filtration curves I've seen say it filters blue just fine.

[HarryChiling]

Horrible article with a lot of wrong information in them. First off a simple way to determine the color that blocks another is to use a color wheel. A particular color will be blocked by it's complementary color on the wheel. Therefore blue will be blocked by orange (amber in our sense).

NOIR are not blue blockers either and have nothing to do with the blue end of the spectrum on thr cotrary they are on the opposite end of the visible or just invisible spectrum they block infrared (No IR).

They appear tinted, but they do not reduce overall light or make the world look darker.

Blue is part of the "overall light" ROYGBIV Red, Orange, Yellow, Green, Blue, Indigo, Violet. Since their are 7 colors in the spectrum then blocking one of them leaves you with at least a 1/7th reduction in visible light. Not to mention that the indigo and violet end of the spectrum are going to be effected by a blue blocker. Plus the overall intesity of the tint is going to absorb a percentage of the other wavelengths just not as much as the blue.

Color Wheel below CC from http://www.worqx.com/color/color_wheel.htm

[Chris Ryser]

OK, I don't get it. They "appear" dark but don't darken: filter selectively and "improve color contrast", yet don't affect the accuracy of color vision. They are apparently OK for night use, although a thread last week clearly concluded that any tint was too much at night

They actually can absorb 50 - 70% of visible light and are definetely nor for night driving.
However the brighten things up during daylight.

The article does not really talk about color combinations but Macular degeneration.

[Chris Ryser]

+

Blue is part of the "overall light" ROYGBIV Red, Orange, Yellow, Green, Blue, Indigo, Violet. Since their are 7 colors in the spectrum then blocking one of them leaves you with at least a 1/7th reduction in visible light. Not to mention that the indigo and violet end of the spectrum are going to be effected by a blue blocker. Plus the overall intesity of the tint is going to absorb a percentage of the other wavelengths just not as much as the blue.

Yellow Light

The visible yellow light has a wavelength of about 570 nm. Low-pressure sodium lamps, like those used in some parking lots, emit a yellow (wavelength 589 nm) light.

Orange Light

The visible orange light has a wavelength of about 590 nm.


Red Light

The visible red light has a wavelength of about 650 nm. At sunrise and sunset, red or orange colors are present because the wavelengths associated with these colors are less efficiently scattered by the atmosphere than the shorter wavelength colors (e.g., blue and purple). A large amount of blue and violet light has been removed as a result of scattering and the longwave colors, such as red and orange, are more readily seen

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