Operational Based Vision Assessment Cone Contrast Test: Description and Operation
Gaska J, Winterbottom M, van Atta A. Operational Based Vision Assessment Cone Contrast Test: Description and Operation. USAF School of Aerospace Medicine, Aeromedical Research Department Wright-Patterson AFB; 2016 Jun 1.
The Diabetes Visual Function Supplement Study (DiVFuSS)
Chous AP, Richer SP, Gerson JD, Kowluru RA. The diabetes visual function supplement study (DiVFuSS). British Journal of Ophthalmology. 2015 Jun 17:bjophthalmol-2014.
Evaluation of Acquired Color Vision Deficiency in Glaucoma Using the Rabin Cone Contrast Test
Niwa Y, Muraki S, Naito F, Minamikawa T, Ohji M. Evaluation of Acquired Color Vision Deficiency in Glaucoma Using the Rabin Cone Contrast TestRabin Test for Glaucoma Color Vision Deficiency. Investigative ophthalmology & visual science. 2014 Oct 1;55(10):6686-90.
Visual function endpoints in early and intermediate dry age-related macular degeneration for use as clinical trial endpoints
Cocce K, Stinnett S, Vajzovic L, Horne A, Toth CA, Cousins SW, Lad EM. Visual function endpoints in early and intermediate dry age-related macular degeneration for use as clinical trial endpoints. Investigative Ophthalmology & Visual Science. 2017 Jun 23;58(8):3765-.
Rabin Color Cone Contrast Testing and Retinal Structure in Multiple Sclerosis
Samuel A, Yiu H, Songster C, Bolivar D, Gelfand J, Green A. Rabin Color Cone Contrast Testing and Retinal Structure in Multiple Sclerosis (P3. 227). Neurology. 2015 Apr 6;84(14 Supplement):P3-227.
Evaluation of visual function impairments in patients with dry age-related macular degeneration
Lad EM, Chandramohan A, Ventura A, Cousins SW. Evaluation of visual function impairments in patients with dry age-related macular degeneration. Investigative Ophthalmology & Visual Science. 2014 Apr 30;55(13):5213-.
Rapid Quantification of Color Vision: The Cone Contrast Test
Rabin J, Gooch J, Ivan D. Rapid quantification of color vision: the cone contrast test. Investigative ophthalmology & visual science. 2011 Feb 1;52(2):816-20.
Evaluation of clinical validity of the Rabin conecontrast test in normal phakic or pseudophakiceyes and severely dichromatic eyes
Fujikawa M, Muraki S, Niwa Y, Ohji M. Evaluation of clinical validity of the Rabin cone contrast test in normal phakic or pseudophakic eyes and severely dichromatic eyes. Acta Ophthalmologica. 2017 May 31.
A Performance Comparison of Color Vision Tests for Military Screening
Walsh DV, Robinson J, Jurek GM, Capó-Aponte JE, Riggs DW, Temme LA. A Performance Comparison of Color Vision Tests for Military Screening. Aerospace medicine and human performance. 2016 Apr 1;87(4):382-7.
A MONTE CARLO SIMULATION OF FOUR CONTRAST THRESHOLD ESTIMATION TECHNIQUES: CLINICAL VISION TEST SELECTION FOR OPERATIONALLY-BASED VISION ASSESSMENT
Winterbottom, M., J. P. Gaska, S. T. Wright, and J. M. Gooch. “Monte Carlo simulation of four contrast threshold estimation techniques: clinical vision test selection for Operationally-Based Vision Assessment.” Aviation, Space, and Environmental Medicine 83, no. 3 (2012).
Assessment of Color Vision Screening Tests for U.S. Navy Special Duty Occupations
Reddix M, Williams H, Kirkendall C, Eggan S, Gao H, Wells W, O’Donnell O. AsMA 85th Scientific Meeting. May 2014.
The US Army Color Vision Study
Capó-Aponte J, Temme L, Robinson J, Still D (May 2014). The US Army Color Vision Study. AsMA.
Pilot Color Vision Research and Recommendations
Millrun N, Chidester T, Peterson S, Roberts C, Perry D, Gildea K. AsMA. May 2013.
Drug-Induced Ocular Side Effects
Fraunfelder, Fraunfelder, Chambers. Drug-Induced Ocular Side Effects. Elsevier Saunders, 2015: 358.
Clinical Ocular Toxicology Drugs, Chemicals and Herbs
Fraunfelder, Fraunfelder, Chambers. Clinical Ocular Toxicology. Sanders Elsevier, 2008: 320.
Cone-specific measures of human color vision
Rabin J. Cone-specific measures of human color vision. Investigative ophthalmology & visual science. 1996 Dec 1;37(13):2771-4.
Konan Medical is a corporate sponsor and supporter of AsMA Aerospace Medical Association
- Protan = L-cone (red) deficiency
- Deutan = M-cone (green) deficiency
- Tritan = S-cone (blue) deficiency
- Genetics Overview
Protan Factoids:
- L-cone deficiency
- Less discrimination of the red colors
- Similar functionally to Deutans
- Significantly more common in males (mutation on X-chromosome allele)
- Commonly genetic cause, but may be acquired
A person with “red deficiency” or “red weakness” is a Protan and the condition is called Protanomaly. The appearance of “redness” by a color normal observer is seen more weakly by the Protan viewer both in terms of its color power (saturation or depth of color) and its brightness. Red, orange, yellow, and yellow-green appear somewhat shifted in “hue” (another word for color) towards green and appear less intense that they do to a color normal observer. The redness portion of a violet or lavender color is also weakened with a Protan so what appears contains mostly the blue component of the color. Thusly, what a color normal calls “violet, may appear only as another shade of blue to the Protan.
Under poor viewing conditions, such as when driving in dazzling sunlight or in rainy or foggy weather, Protan observers may mistake a blinking red traffic light for a blinking yellow, or fail to distinguish a green traffic light from the “white” lights in store fronts, street lights or other general lighting.
Deutan Factoids:
- M-cone deficiency
- Less discrimination of the green colors
- Similar functionally to Protans
- Significantly more common in males (mutation on X-chromosome allele)
- Commonly genetic cause, but may be acquired
A person with a Deutan deficiency called Deuteranomaly (5% of males) is considered to be “green weak” This deficiency is similar to the Protan type as there is also difficulty in discriminating between red – orange – yellow – green portions of the color spectrum … they are confused as being very similar. These colors seemed similar to the red portion of the spectrum.
Deuteranopia (1% of males) has the same hue discrimination problems as the Protonope, but without the dimming.
Tritan Factoids:
- S-cone deficiency
- Less discrimination of the blue colors
- Typically an acquired condition (genetic basis is very rare)
- May be the most common color deficiency type
- No gender bias
- Many tests that have been commonly administered in the past (Ishihara as an example) do not test for S-cone deficiencies
- More common with age
- Pharmaceutical agent toxicity may cause
- Neurologic conditions, diseases and discorders may cause
- Changes to the crystalline lens (cataracts) may cause
Red-green color deficiencies are the most common type of genetic color vision deficiency, originating from an X-chromosome mutation which results in a color deficient allele.
This is a recessive trait, but females that are heterozygous (trait only on one X-chromosome) will not exhibit the inherited trait, rather it requires a homozygous condition where the trait is manifested on both chromosomes, i.e. inherited from both parents.
Males, that inherit trait on the single X-chromosome maternally, exhibit red-green color deficiency.