Posted by Alexandra Wilgosh on July 19, 2000 at 13:29:55:
I posted a message here a few months ago, just after my 35-year old husband was diagnosed with 'dry' MD. I have two questions that I haven't been able to resolve with my on-line research.
1) which type of lighting is better, halogen or flourescent?
2) what colour lens best blocks blue light?
Thanks in advance, and I always learn heaps when I go online and read this forum. Thanks Dan and Judy for all your hard work and support!!
Alexandra
Posted by Shannon Ball on August 14, 2000 at 12:14:31:
In Reply to: Indoor Lighting & Sunlight posted by Alexandra Wilgosh on July 19, 2000 at 13:29:55:
: 1) which type of lighting is better, halogen or flourescent?
: 2) what colour lens best blocks blue light?
I'm just learning about Macular Degeneration, but I've been an optical engineer for 35 years. The answers to your questions are:
1. Tungsten halogen lamps are just brighter filament light bulbs, with halogen gas added for longer life and better power handling. They are weak in ultraviolet, except where a high-powered one just has much more of the full spectrum. Household light bulbs are very weak in ultraviolet output.
Fluorescent lamps have high outputs in the blue and ultraviolet spectral regions, as do large mercury vapor lamps used in some large stores and warehouses.
To avoid lamps high in blue and ultraviolet, stay with tungsten lamps, including tungsten halogen, and avoid fluorescent and mercury lamps.
2. The color of lens or filter for the best blocking of blue light would be anything pink or darker toward the red. Some light tan lenses filter it well, also. Many of the photo-chromic (self-darkening) lenses used in eyeglasses are excellent blockers of ultraviolet. They keep a light tint at all times, and are perfect for office work under fluorescent lights.
An excellent test of the ability to block ultraviolet may be seen around a "black light" found in some displays and nightclubs. The liquid vitreous humor in the eyeball is naturally fluorescent (it glows when struck by ultraviolet light). In a generally dark ambient environment, with a "black light" overhead in front of you, you will see a slight haze across the entire scene when the ultraviolet enters your eye. Placing the glasses over your eyes, to shield you from the ultraviolet, should make the haze go away if the glasses are good ultraviolet blockers. Flipping the glasses up and down over your eyes may make it easier to see. To see the glow initially, you may need to place your hand over your eyes, as if shielding your eyes from the sun. Then, moving your hand to create an alternating on-off shadow for the ultraviolet should make it easy to see the glow inside your eyes.
Use only the small "black light" systems used to show off fluorescent paints and dyes. The high powered ones used in photolithography and in mineral studies are a little too bright to be safe to look at. Novelty gift shops that sell fluorescent signs and dyes usually have "black lights" on the ceiling. The party lights from Radio Shack also are good for such tests.

By Bilal Safdar on Monday, April 16, 2001 - 12:12 am:

Somebody close to me has been diagnosed with Macular Degeneration. I would like to know more about light toxicity within the context of this disease. Regards,

Bilal

By VasiliY_ya on Saturday, May 27, 2006 - 05:10 pm:

I know where you can buy phentermine discount
( [link=http://phentermine-discount.ownsite.ru/downloadfiles/7119] phentermine discount [/link] )
( [URL=http://phentermine-discount.ownsite.ru/downloadfiles/7119] phentermine discount [/URL]) in florida. Medicine phentermine.

By VasiliY_ya on Saturday, May 27, 2006 - 05:02 pm:

I know where you can buy phentermine discount
( [link=http://phentermine-discount.ownsite.ru/downloadfiles/7119] phentermine discount [/link] )
( [URL=http://phentermine-discount.ownsite.ru/downloadfiles/7119] phentermine discount [/URL]) in florida. Medicine phentermine.