The Rabin Cone Contrast Test is a diagnostic tool used to assess a patient’s ability to detect subtle contrast differences, particularly in the context of visual dysfunctions related to conditions like glaucoma, optic neuropathies, and other diseases that affect the visual system.
The RCCT is a quantitative and highly sensitive test that measures the contrast sensitivity of each cone type in the eye individually. Unlike basic color vision screening (like Ishihara plates), RCCT provides:
- Precise measurement of color vision ability
- Detection of mild to severe deficiencies
- Reliable documentation for occupational and clinical purposes
This test is especially important in settings where normal color vision is a critical requirement.
Understanding Color Vision Deficiency (Color Blindness)
Color vision deficiency, commonly referred to as color blindness, affects approximately 1 in 12 men and 1 in 200 women. It occurs when one or more of the cone photoreceptors in the eye—responsible for detecting color—are absent or not functioning properly. When one of these cone types is deficient, it results in difficulty distinguishing between specific colors, most commonly reds and greens, or blues and yellows.
Why Accurate Color Vision Testing Matters
Everyday Impact
Even outside specialized professions, color vision affects:
- Driving: Reading traffic signals and signs
- Education: Interpreting color-coded information in textbooks or slides
- Workplace Safety: Recognizing warning labels, wires, and hazard indicators
Aviation and Piloting
Color perception is crucial for:
- Reading cockpit instruments with color-coded indicators
- Recognizing runway and navigation lights
- Interpreting warning signs and displays
FAA regulations require specific color vision standards for pilots. The RCCT is recognized for providing the high level of detail needed for certification or waiver processes.
Military Service
Many military roles demand normal color vision, particularly:
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Aviation and drone operation
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Electrical or engineering duties
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Medical and surgical roles
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Intelligence and surveillance
The Rabin CCT is used by the Air Force, Army, Navy, and Coast Guard for color vision screening. It is also approved by the FAA for color vision testing for pilots, and is one of the three FAA-approved computerized color vision tests.
Key Aspects of the Rabin Cone Contrast Test™
- Target Type: The test usually involves patterns or visual stimuli that consist of concentric rings or “cones,” often resembling a set of circles or disc-like shapes.
- Contrast Variability: These patterns are presented at varying contrast levels, with the primary goal being to determine the lowest contrast at which the patient can still identify the target.
- Assessment of Sensitivity: The test evaluates contrast sensitivity, which refers to the ability to detect differences between an object and its background. This is critical for tasks such as reading, driving, and recognizing faces, especially in low-light conditions or when there are subtle variations in the visual scene.
Benefits of the Rabin Cone Contrast Test™
- Early detection of of contrast sensitivity loss, which can be an early sign of eye diseases like glaucoma or optic neuropathy.
- More accurate reflection of real-world visual function, especially in low light, glare, or complex visual conditions.
- Useful in monitoring disease progression, especially for diseases affecting the optic nerve or other visual conditions.
- Non-invasive and quick, making it suitable for routine screening and follow-up assessments.
FAA Color Vision Testing Policy Change as of Jan 1, 2025
FAA NEW POLICY CHANGES
The Rabin Cone Contrast Test (CCT) has been approved as 1 of 3 required color vision tests for all commercial pilots.
- Pilots must pass 1 of the required color vision tests or be issued a flying restriction by the FAA.
- Rabin Cone Contrast Test can be taken if they fail any other approved test.
- Periodic testing is required for pilots with a medical condition, or who are taking a medication, which affects color vision.
- Optometry practices can administer initial, retest, and periodic FAA color vision tests.
- Most FAA color vision exams using the Rabin Cone Contrast Test can be billed to insurance.
- All optometry practices with the Rabin Cone Contrast Test will be included on a FAA Pilot Referral List.
ROUTINE COLOR VISION SCREENING
In addition to one-time hereditary color vision screening, routine color vision screening must be performed for all commercial pilots with a medical condition, or who takes a medication, which could affect color vision. Conditions include:
- Eye conditions such as glaucoma, AMD, retinal detachment, or cataracts
- Brain and nervous system conditions such as Alzheimer’s, MS, or certain tumors
- Medical conditions such as diabetes, alcoholism, leukemia
- Medications such as Plaquenil, blood pressure medications, and erectile dysfunction medications
- Other conditions affecting color vision
RABIN CONE CONTRAST RULES FOR FAA EXAM
- Administration of the test is the same as for medical patients:
- Use “Test at Near”
- Ensure the patient is seated 3’ from device
- Test monocularly
- Color correction lenses are not approved to be used during the test
- For best results:
- Avoid using blue filters
- For dry eye patients, administer dry eye drops before the test and advise the patient to blink throughout test
- Passing score for Class 1 flying is 55 in all cone types/ both eyes. Rabin CCT software upgrades are available to reflect FAA passing score. Please contact Innova Systems.
- All tests must be performed in person; on-line testing is forbidden
- Pilots can retake the Rabin CCT up to 3 times. The best results of the 3 tests should be reported.
- Reports should be printed and given to the pilot for uploading to the FAA
BILLING FOR RABIN CONE TESTING
- The cost of the Rabin Cone Contrast Test for FAA or military is $150 Out of pocket as an additional service on top of an exam (not included in an annual eye exam).
- Initial color vision tests are routinely charged to the pilot
- Retests can be billed to insurance, regardless if the failure was due to a hereditary or acquired color vision deficiency. A copy of a previously failed color vision test or diagnosis is required. See the Rabin CCT Utilization & Billing Protocol for more details.
- The Rabin CCT is covered under some medical insurance for purposes such as Diabetic exams and Glaucoma evaluation.
Please note: The Rabin Cone Contrast Test is not covered by insurance and is offered as an out-of-pocket service.
Why Choose Rabin Cone Contrast Testing at Our Office?
At our clinic, we offer cutting-edge vision assessments, including the Rabin Cone Contrast Test, to:
- Accurately diagnose color deficiencies
- Support occupational testing needs (FAA, military, etc.)
- Help patients understand how color vision impacts daily life
Whether you’re pursuing a career in aviation, military service, or simply want clarity on your color perception, we’re here to provide the best in modern optometric care.
