Very nice to hear from you!
The jury is still out on colored glasses for the color-blind. There is some science behind it, but the benefits are a little iffy and depend on the specific degree of color-blindness of the individual and the environmental conditions and uses for the color vision.
The basic idea is to use a tinted lens to shift the wavelengths of environmental colored light more towards the red end of the spectrum (longer wavelength) to enhance color CONTRASTS, and not to restore true color perceptions. This only works well in conjunction with the specific color deficiencies of the person, the luminance levels in the environment, the degree of color contrast inherent in the specific area of environment concerned, the wavelengths of color that are important in the environment, and the usefulness of enhanced contrast for the specific task.
In terms of green reading for golf putting, the enhanced color contrast in the green surface may reveal surface detail with richer visual information. The typical color filter works most in the green-to-red area of the spectrum, with green being in the middle and red at the long end of wavelengths, and blue-violet at the short end. The red-yellows of tawny grass specks or spots on the green may be seen with better contrast, and some enhanced contrasts of different shades of green may show up. This added visual information allows better detection of surface contour, because detection of surface contour depends upon the diminution of apparent size of surface detail in a pattern that differs for level, versus tilted towards the observer, versus tilted away from the observer. Detail is contrast at the edges.
I've previously written about Color Blindness and Putting on the Flatstick Forum, here
. Another posting covers sunglasses for putting, here
This Vischeck website
has some very good discussions and interactive features about color blindness.
The International Colour Vision Society
is the top organization studying these issues. Their newsletter Daltoniana has lots of information.
Here's a pretty good overview:
Review of Optometry
JOSEPH P. SHOVLIN, O.D.
OPTIONS FOR COLOR-DEFICIENT PATIENTS
Q: Are there any contact lenses that will allow a red-green color-blind patient to pass the Ishihara test?
A: Yes. There are several tinted contact lenses that can help this patient pass the Ishihara test. More specifically, by selectively eliminating certain wavelengths, tinted lenses may help this patient distinguish some of the Ishihara numbers and shapes.
Realize, however, that any such lens will not correct color perception deficiencies. Rather, tinted lenses will allow some patients to distinguish some of the Ishihara numbers and shapes.
Timothy McMahon, O.D., of the University of Chicago at Illinois, has reservations about using tinted lenses to help a patient pass the Ishihara test. In most instances, the color vision requirements are valid, and obviating them could put the patient or others in jeopardy.
A magenta soft contact lens may help color-deficient patients see more colors. Dr. McMahon offers this scenario: A police officer is sent to a crime scene and told that a homeowner is holding off an intruder with a gun. The officer is informed that the perpetrator is wearing a red jacket and the homeowner a black one. If he has a red color deficiency, he may be unable to distinguish the two and could make a critical mistake. "Sure, this is an extreme and unlikely scenario, but the potential consequences could be devastating," Dr. McMahon says.
That said, contact lens correction is often a good option for helping patients with color perception deficiency resolve some shapes and numbers on the Ishihara test. While tinted spectacles are an option, too, contact lenses are a first choice for these reasons: full pupil coverage, limited peripheral glare and greater selective spatial transmission due to a reduced number of optical surfaces. Most patients with retinal conditions demonstrate better comfort and visual performance with contact lenses than with spectacles.
You can often enhance a patient's ability to discriminate colors with a red filter in one eye. This has a greater effect for deutans (patients with green deficiency) than for protans (those with red deficiency).
Private optometrist Jay Schlanger of Los Angeles has had success in helping these patients by fitting a magenta soft lens in one eye for protans.
Previously, contact lens treatment for red-green color deficiencies relied on a monocular dark red rigid lens. The X-Chrom lens used in the 1980s was a PMMA lens that transmitted light in the 590-700 wavelength range. Today, there are more options. Joel M. Silbert, O.D., professor of optometry and director of the Cornea and Specialty Contact Lens Service at Pennsylvania College of Optometry's Eye Institute in Philadelphia, prefers Trans-Aire, an extra dark RGP lens.
A soft lens option Dr. Silbert suggests: ChromaGen. This series of lenses is available in a range of 26 tints in spherical or toric designs. A variety of hues, densities and pupil sizes are available to suit your patient's needs. Dr. Silbert suggests using a dark red zone that's restricted to the central 5-7mm zone.
Be aware that some patients with severe red deficiency may suffer an extreme red loss. A red lens may reduce acuity in these patients.
You may want to design a custom tinted lens for your patient. Several companies do custom lens tinting on an individual basis. Three that Dr. Silbert uses: Adventure in Colors in La Jolla, Calif.; Crystal Reflections International in Green Valley, Ariz. (www.crystalreflection.com); and Specialty Tint Corporation in Salt Lake City (www.specialtylens.com).
No matter what lens you choose, explain to the patient that while the lens will enhance his or her ability to visualize color differences, it does not correct color deficiency. Instruct him or her to continue to adhere to color vision requirements.
Source for above
Below are snippets from various sources discussing color-blindness therapeutic or prosthetic devices.
*number 91 - February, 1999
The bulletin of the International Colour Vision Society
There has been a good deal of media coverage of the Chromagen lens from the UK and the Color-Max lenses from the US. They purport to be "New". They appear to be recycled versions of the X-Chrom lens of Zeltzer in the early 1970s. I take great delight in pointing out that the idea stems from Seebeck in 1817 !! After coverage on Australian national television we were receiving about 6 enquiries per day.
For the full hype on Chromagen
(have your $US220 per lens ready) and on Color-Max
I have an information sheet which we give to prospective patients . Comments and suggestions appreciated. We also carried out a study in 1998 which showed that it assisted passing the Ishihara test, did not assist passing the Farnsworth Lantern Test and some people throught it improved their perception dramatically.
For an inexpensive and useful aid to teaching colour see ColorCube.com
Source for above
FDA TALK PAPER
Food and Drug Administration
U.S. Department of Health and Human Services
Public Health Service 5600 Fishers Lane Rockville, MD 20857
FDA Talk Papers are prepared by the Press Office to guide FDA personnel in responding with consistency and accuracy to questions from the public on subjects of current interest. Talk Papers are subject to change as more information becomes available.
T99-58 Sharon Snider: 301-827-6242
December 21, 1999
Consumer Media: 888-INFO-FDA
The FDA has received a number of media inquiries about ColorMax eyeglass lenses, which are being promoted widely as a way to correct color blindness. Some of the claims in these promotions may be misleading.
The following can be used to answer questions:
* ColorMax lenses, made by Color Vision Technologies, Inc., Tustin, Calif., were cleared for market by FDA in November. They are tinted prescription spectacle lenses intended as an optical aid for people with red-green color vision deficiencies. The lenses do not help wearers perceive or appreciate colors as people with normal color vision do, but merely add brightness/darkness differences to colors that are otherwise difficult or impossible to distinguish.
* ColorMax lenses are designed to improve discrimination of specific colors that look the same to people with regreen color deficiencies. However, discrimination of at least some other colors is actually impaired.
* ColorMax lenses are not effective for people who are totally color blind. Very few people are truly color blind, and these lenses will not help them to see colors. Most people with color vision problems have partial color vision deficiencies that make it difficult to distinguish between red and green or between yellow and blue. FDA marketing clearance for ColorMax Lenses is limited to red-green color deficiencies, and does not include yellow-blue deficiencies or total color blindness.
* ColorMax lenses are coated with colored filters using a technology similar to that used to apply anti-reflection coatings on spectacles and colored coatings on prescription sunglasses. The coating process is not new or "high-tech" as stated in some of the company's promotional reports.
* Although ColorMax lenses are the first such lenses to be cleared by FDA for commercial marketing in the United States, the idea is far from new. The use of colored filters as an optical aid for color deficiency has been reported in the scientific literature since the 1850's,and at least two textbooks on color vision deficiencies contain entire chapters on the subject.
* The Colormax lenses were cleared for marketing through the FDA's regular premarket review process. Contrary to reports, no special class of devices was created by FDA for these products.
* FDA has determined that ColorMax lenses are substantially equivalent to prescription spectacle lenses. The manufacturer conducted clinical studies to support a new indication for use as an optical aid for red-green color vision deficiencies.
* FDA is currently looking into the claims being made for this product.
New eyeglasses designed to help people with colorblindness
April 21, 2000
Web posted at: 11:12 AM EDT (1512 GMT)
By Jim Dawson
(WebMD) -- When optometrist Frank Siciliano, O.D., first saw an advertisement for ColorMax eyeglass lenses, he took more than a professional interest. Siciliano, who runs the Belmont Eye Clinic in Youngstown, Ohio, is colorblind himself and knows the frustration of not being able to see the world in full, brilliant color.
Last September he contacted ColorMax Technologies, Inc., the Tustin, California, company that developed the lenses, and became one of the first optometrists to both wear and prescribe them to improve his red-green colorblindness.
"There is no question they work," he says. "They are like wearing sunglasses, but they enhance reds. They brighten and lighten the shades you now see as dark and washed out. And the problem with greens is they aren't dark enough. With the lenses, the greens are much darker and you can see contrasts."
By slipping on eyeglass lenses with a unique coating that "fine tunes" the light entering the eyes, many of the 12 million colorblind people in the United States may, for the first time, be able to improve their ability to perceive some colors. James Bailey, O.D., Ph.D., a member of ColorMax's science advisory board and a faculty member at the Southern California College of Optometry in Fullerton, emphasizes that the new lens coating is not a cure for colorblindness. He calls it "an optical and therapeutic aid that helps (some colorblind people) better use what vision they have."
"Anybody who works with surface colors, such as electricians, assemblers of color-coded parts, cooks who have to judge when meat is done or aviators reading radar screens, might be helped with these lenses," says Bailey. Although they are only available for people suffering from red-green colorblindness, that represents 80 percent of those who have color vision problems.
Colorblindness, or more accurately color vision deficiency, mostly affects men and tends to run in families. As many as one in 12 men has some degree of this condition, as compared to about one in every 250 women. Besides difficulty with red-green perception, some people have other color vision problems, such an inability to distinguish yellows from blues. In very rare cases, a person may be truly colorblind and see only shades of black and white.
The ColorMax lenses work by shifting the wavelengths of the light entering the eye towards the longer end of the visible spectrum, Bailey says, making it easier for the eye to distinguish between the "warm" colors -- reds, yellows and oranges. However, the wavelengths of colors at the shorter end of the spectrum -- blues and purples -- are also shifted. These may actually become slightly harder to distinguish. Greens fall in the middle and are less noticeably affected. The result is not "normal" vision, but an enhanced contrast between colors.
When Siciliano first tried the lenses, he could instantly see many more variations in shades of color. "You have to relearn all of the colors with the glasses on," he says. "Someone has to tell you that 'that is red.' You say, 'OK, that's red,' and work from there."
Even the U.S. Food and Drug Administration (FDA) was careful to point out limitations of the ColorMax lens coating technique when it approved it last November. "The lenses do not help wearers perceive or appreciate colors as people with normal color vision do, but merely add brightness/darkness differences to colors that are otherwise difficult or impossible to distinguish," says an FDA "Talk Paper." The FDA adds that any promotion of the lenses as "a way to correct colorblindness" may be "misleading."
Many eye experts are similarly cautious. "The problem is that there is not a lot of information available to judge them," says Jeffrey Weaver, O.D., the director of the clinical care group of the American Optometric Association. "I don't have the clinical trial information, although I've asked for it. I'm not going to be convinced of anything until the ColorMax researchers publish a paper on it."
Ophthalmologist Joel Pokorny, Ph.D., of the University of Chicago's visual sciences department, says he is "open" to the idea of the lenses, "but I don't think you're going to gain much. There is a theoretical possibility that they could improve some discrimination of color in the real world, but it's a trade off. You will lose some discrimination as well. But overall, they could help a little bit."
That little bit of help isn't cheap -- $699 for a pair of adult lenses, $499 for children's glasses. The high price reflects extensive research and development costs, according to the company. Pokorny called the price "way out of line" considering the limited improvements in vision.
Still, some colorblind patients are clearly willing to give the lenses a try. Siciliano has fit 15 people with them, "but they are new enough that we haven't had feedback yet. Some people need to distinguish among colors for their jobs, he said, while others "are motivated by simply being able to do better color matching of their clothes."
On Target Weekly Journal
VII. FDA back to top
TARGET HEALTH excels in Regulatory Affairs and works closely with many of its clients and FDA. A pre-IND meeting is scheduled for the first week in October. TARGET HEALTH receives daily updates of new developments at FDA. Each week, highlights of what is going on at FDA are shared to assure that new information is expeditiously made available. For additional information, please contact Dr. Jules T. Mitchel at TARGET HEALTH.
Most people with color vision problems have partial color vision deficiencies that make it difficult to distinguish between red and green or between yellow and blue. ColorMax lenses (Color Vision Technologies, Inc., Tustin, CA) are coated with colored filters using a technology similar to that used to apply anti-reflection coatings on spectacles and colored coatings on prescription sunglasses. Although ColorMax lenses are the first such lenses to be cleared by FDA for commercial marketing in the United States, the idea is far from new. The use of colored filters as an optical aid for color deficiency has been reported in the scientific literature since the 1850's, and at least two textbooks on color vision deficiencies contain entire chapters on the subject. FDA marketing clearance for ColorMax Lenses is limited to red-green color deficiencies, and does not include yellow-blue deficiencies or total color blindness. The FDA has received a number of inquiries about ColorMax eyeglass lenses which are being promoted widely as a way to correct color blindness. Some of the claims in these promotions may be misleading. Contrary to reports, no special class of devices was created by FDA for these products.
Duke University Occupational and Environmental Medicine Discussion Forum
Date: Thu, 30 Dec 1999 01:26:42 -0500
Sender: Occupational & Environmental Medicine for Clinicians & Public
From: Gary Greenberg <Gary.Greenberg@DUKE.EDU>
Subject: Color vision Rx: Impressions / experiences?
A new lens "treatment" for impaired color vision has been (briefly!)
discussed in many popular media outlets.
I just visited the site for the manufacturer
, and have
- this is a legitimate, FDA approved technique (though the agency sounds
VERY skeptical, see below!)
- prescribing the lenses requires(?) owning special software for color
vision assessment and ?treatment
- optometrists need to license (?)something, and then they'll be listed
in the directory of ColorMax professionals
- presently there're only 6 locations in the US listed: 3 in CA, 1 each
in IA, OH, NY
- the treatment seems to work by providing a color filter by enhancing
contrast between hues that would have otherwise seemed identical. Do
others read this webpage and get the same impression?
I wonder what our discipline will make of this for professions requiring
-> Do you think that filter-wearing individuals who pass this test
should be certified as unimpaired?
-> Will we declare this another corrective lens requirement, and state
that the individual is approved, but must wear corrective lenses?
I'm interested in impressions (even 1st hand) by those who have tried
this technique. Aside from the professional questions that seem pretty
interesting, my own son is very color vision-impaired, and was VERY
excited to hear of this development.
- Gary Greenberg
Date: Thu, 30 Dec 1999 07:26:04 -0500
Sender: Occupational & Environmental Medicine for Clinicians & Public
From: Natalie Hartenbaum <NataH@WORLDNET.ATT.NET>
Subject: Re: Color vision Rx: Impressions / experiences?
Even the company that has produced these and similar lens has acknowledged
that the color vision deficiency is not corrected only that the individual
is better able to distinguish colors by differences in contrast. The
earlier marketed ( and still available) x-chrom lens is not acceptable in
pilots or air traffic controllers nor by railroad engineers except in
certain circumstances. A review of the x-chrom lens can be found in
Hartenbaum NP. The X-Chrom Lens and color deficiency - Occupational
Medicine Forum, JOEM 1998;40:518-519
Q&A with Dr. Terrace L. Waggoner
Question from Chris: Protanopia and Deuteranopia - I have been diagnosed with the above visual abnormalities and I am currently a holder of a US Pilot's License. As I have been diagnosed this affects my night flying ability. Is there any way this can be corrected using specific lenses either in glasses or contact lenses?
Answer: To my knowledge, congenital (you're born with it) colorblindness is permanent and there is no cure or treatment. Tinted lenses, reportedly for colorblindness, have been recently introduced. For further information on two of these new lenses, you can visit their promotional websites (IMPORTANT UPDATE 12-05-2003 - ColorMax went out of business) and Solarchromic Lenses. The X-chrome Contact Lens (a red tinted monocular contact lens for colorblindness) has been on the market for decades. Yes, these lenses will help you pass some color vision tests, but so would looking through "any" red glass lens or piece of red tinted cellophane. It is unlikely that an examiner (e.g. Federal Aviation Administration) would let you use any of these devices to take their color vision test. Would these new lenses let you identify the red and green lights on an airplane at night or help you correctly identify different colored wires? I do not know. I have not read any credible scientific studies which validate these devices from a practical stand point. Personally, for me the jury is still out on the true benefits of these new devises.
Solaz Solarchromic Lenses
Solaz sunglasses with solar-powered laser dye coated lenses make colors so bright... so clear... so vivid...that you will hardly believe your eyes!
Discovered by accident and patented after years of research and development, the high-tech lenses we use in our sunglasses provide unique visual benefits so dramatic they must be seen to be believed. You will see an amazing increase in the purity and saturation of colors, with improved contrast as well.
Studies also suggest that these extraordinary sunglasses can improve color perception of red and green in persons with deficient color vision, with colorblind subjects scoring higher on tests when using the lenses.
X-Chrom lenses are contact lenses for those with red/green color blindness. It is a deep red lens worn in the nondominant eye and intensifies the color of red and green objects. This allows the nondominant eye to feed information to the brain about colors it could previously not determine. The dominant eye continues to relate information about colors that it normally sees. The lens is not a cure for color blindness, but is an aid in the improvement of color perception.
Journal of Occ & Env Med
Can corrective lenses effectively improve a color vision deficiency when normal color vision is required?
Journal of Occupational & Environmental Medicine. 40(6):518-519, June 1998.
Many law enforcement, transportation, and other government jobs requiring color vision for safety disallow X-Chrom lenses.
LAS VEGAS METROPOLITAN POLICE DEPARTMENT
POLICE/CORRECTIONS APPLICANT VISION STANDARDS:
III. Color Blindness (Police / Corrections)
1. A significant loss of color vision (greater than two crossings - of 4 or greater) on the Farnsworth D-15 panel test is unacceptable.
2. The use of X-chrom lenses is prohibited.
3. Candidates who fail the Ishihara and pass the Farnsworth D-15 are acceptable.
4. Candidates who fail both the Ishihara and the Farnsworth D-15 are not acceptable.
FAA and Pilots
Does the FAA allow pilots to wear lenses that correct color vision?
Although no eyeglasses will correct a color vision deficiency, a contact lens called X-Chrom can partially correct it. The problem is that while X-Chrom lenses can help your vision in one way, they can impair it in other ways. Because of this, the FAA does not allow pilots to wear them.
FAA Guide for Medical Examiners:
EXAMINATION TECHNIQUES AND CRITERIA FOR QUALIFICATION
ITEM 52. Color Vision (pages 88 ff.)
I. CODE OF FEDERAL REGULATION
All Classes: 14 CFR 67.103(c), 67.203(c), and 67.303(c)
***Ability to perceive those colors necessary for the safe performance of airman duties.
II. EXAMINATION PROCEDURES
1. Pseudoisochromatic plates. (American Optical Company [AOC], 1965 edition; AOC-HRR, 2nd edition; Dvorine, 2nd edition; Ishihara, 14-, 24- or 38-plate editions; or Richmond, 1983 edition, 15-plates).
2. Acceptable substitutes:
• Farnsworth Lantern.
• Keystone Orthoscope.
• Keystone Telebinocular.
• LKC Technologies, Inc., APT-5 Color Vision Tester.
• OPTEC 2000 Vision Tester (Model Nos. 2000PM, 2000PAME, and 2000PI).
• Titmus Vision Tester.
• Titmus II Vision Tester (Model Nos. TII and TIIS).
• Titmus 2 Vision Tester (Model Nos. T2A and T2S).
1. The test plates to be used for each of the approved pseudoisochromatic tests are:
Test Edition Plates
AOC 1965 1-15
AOC-HRR 2nd 1-11
Dvorine 2nd 1-15
Ishihara 14-Plate 1-11
Ishihara 24-Plate 1-15
Ishihara 38-Plate 1-21
Richmond 1983 1-15
2. The following conditions should be ensured when testing with pseudoisochromatic plates:
a. The test book should be held 30 inches from the applicant.
b. Plates should be illuminated by at least 20 foot candles, preferably by a Macbeth Easel Lamp or a Verilux True Color Light (F15T8VLX).
c. Three seconds should be allowed for the applicant to interpret and respond to a given plate.
3. Testing procedures for the Farnsworth Lantern; Keystone; LKC Technologies, Inc.; OPTEC 2000, Titmus, Titmus II, and Titmus 2 Vision Testers accompany the instruments.
4. The results (pass or fail) should be recorded.
An applicant does not meet the color vision standard if testing reveals:
A. All Classes
1. Seven or more errors on plates 1-15 of the AOC (1965 edition) pseudoisochromatic plates.
2. AOC-HRR (second edition): Any error in test plates 7-11. Because the first 4 plates in the test book are for demonstration only, test plate 7 is actually the eleventh plate in the book. (See instruction booklet).
3. Seven or more errors on plates 1-15 of Dvorine pseudoisochromatic plates (second edition, 15 plates).
4. Six or more errors on plates 1-11 of the concise 14-plate edition of the Ishihara pseudoisochromatic plates. Seven or more errors on plates 1-15 of the 24-plate edition of Ishihara pseudoisochromatic plates. Nine or more errors on plates 1-21 of the 38-plate edition of Ishihara pseudoisochromatic plates.
5. Seven or more errors on plates 1-15 of the Richmond (1983 edition) pseudoisochromatic plates.
6. Farnsworth Lantern test: An average of more than one error per series of nine color pairs in series 2 and 3. (See instruction booklet).
7. Any errors in the six plates of the Titmus Vision Tester, the Titmus II Vision Tester, the Titmus 2 Vision Tester, the OPTEC 2000 Vision Tester, the Keystone Orthoscope, or Keystone Telebinocular.
8. LKC Technologies, Inc., APT-5 Color Vision Tester. The letter must be correctly identified in at least two of the three presentations of each test condition. (See APT-5 screening chart for FAA-related testing in instruction booklet).
B. Certificate Limitation
If an applicant fails to meet the color vision standard as interpreted above but is otherwise qualified, the Examiner may issue a medical certificate bearing the limitation:
Not valid for night flying or by color signal control
C. Special Issuance of Medical Certificates
An applicant who holds a medical certificate bearing a color vision limitation may request reevaluation or a SODA under the special issuance section of Part 67 (14 CFR 67.401). This request should be in writing and should be directed to the Aeromedical Certification Division, AAM-300. If the applicant can perform the color vision tasks, the FAA will issue a medical certificate without limitation with a SODA.
Demonstrating the ability to perform color vision tasks appropriate to the certificate applied for may entail a medical flight test or a signal light test. If a signal light test or medical flight test is required, the FAA will authorize the test. The signal light test may be given at any time during flight training.
The medical flight test is most often required when an airman with borderline color vision wishes to upgrade a medical certificate.
D. "Color Vision Correcting" Lens (e.g. X-Chrom)
Such lens are unacceptable to the FAA as a means for correcting a pilot's color vision deficiencies.
E. Yarn Test
Yarn tests are not acceptable methods of testing for the FAA medical certificate.
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