Blue-Yellow Colorblind Test
This test uses specialized blue-yellow pseudoisochromatic plates to screen for tritan-type color vision deficiency, including tritanopia and tritanomaly. Standard Ishihara tests cannot detect these conditions because they only test the red-green axis.
Before you begin
Set up your screen and lighting
Display conditions can materially change an online color vision result. Take a moment to check these items before starting.
- Use a color screen at its normal brightness, viewed straight on.
- Turn off Night Shift, blue-light filters, grayscale, and color filters.
- Use neutral room lighting and avoid glare on the display.
- Wear your usual prescription glasses or contacts, if applicable.
- Use your first impression and answer each plate within about 5 seconds.
What This Test Screens For
Blue-yellow color vision deficiency encompasses tritanopia (blue-blind, absent S-cones) and tritanomaly (blue-weak, shifted S-cones). Both conditions cause confusion between blues and greens, and between yellows and light grays or pinks. Unlike red-green deficiency, blue-yellow deficiency affects men and women at equal rates because the responsible gene is on chromosome 7, not the X chromosome.
Limitations of This Test
This test uses digitally generated plates and is not equivalent to clinical instruments like the HRR plates or Farnsworth D-15 panel. Monitor color reproduction varies significantly and can affect results. This test cannot distinguish tritanopia from tritanomaly. Because acquired tritan deficiency (from cataracts, glaucoma, medications) is more common than inherited tritanomaly, a positive result should prompt a comprehensive eye exam.
What to Expect
You will see 10 circular plates with numbers rendered in blue-violet tones against yellow-gold backgrounds. People with normal blue-yellow discrimination will see the numbers clearly. People with tritan-type deficiency will have difficulty because the color difference falls on their confusion axis. The test takes 2-3 minutes.
Why You Need a Separate Blue-Yellow Test
The vast majority of color vision screening uses Ishihara plates, which only detect red-green deficiency. If you have taken a standard colorblind test and received a normal result, you have only been screened for about 95% of color vision deficiencies. The remaining 5% involve blue-yellow confusion (tritan deficiency) and require plates designed along a completely different color axis, which is what this test provides.
Inherited vs. Acquired Blue-Yellow Deficiency
Inherited blue-yellow deficiency (tritanopia, tritanomaly) is very rare, affecting approximately 0.003-0.001% of the population. However, acquired tritan-type deficiency is surprisingly common, particularly in people over 50. As the crystalline lens yellows with age, it progressively filters out short-wavelength (blue) light, causing a gradual reduction in blue-yellow discrimination. Cataracts, glaucoma, macular degeneration, and certain medications can also cause acquired tritan deficiency.
Frequently Asked Questions
I passed the standard colorblind test but failed this one. Is that possible?
Yes, absolutely. Standard colorblind tests (Ishihara) only detect red-green deficiency. You can have perfect red-green discrimination and still have blue-yellow deficiency. The two types involve different cone photoreceptors and different genes. That is exactly why separate tests are needed.
Is blue-yellow colorblindness common?
Inherited blue-yellow deficiency is rare (0.003% of the population). However, acquired blue-yellow deficiency from aging or eye disease is relatively common. If you are over 50 and struggling with this test, it may reflect normal age-related changes in your lens rather than a congenital condition.
Does blue-yellow colorblindness affect men and women equally?
Yes. Unlike red-green colorblindness (which is X-linked and predominantly affects males), blue-yellow deficiency is linked to chromosome 7 and affects men and women at equal rates.
Related Tests
Tritanopia Test (Blue-Yellow Blind)
This test uses blue-yellow pseudoisochromatic plates specifically designed to screen for tritanopia and tritan-type color vision deficiency. Unlike standard Ishihara tests, which only detect red-green deficiency, these plates use colors along the tritan confusion axis.
Tritanomaly Test (Blue-Weak)
This test uses blue-yellow pseudoisochromatic plates to screen for tritanomaly, an extremely rare condition where the blue-sensitive (S) cones have altered spectral sensitivity. Standard Ishihara tests cannot detect tritan-type deficiency.
Red-Green Colorblind Test
This Ishihara-style test screens for all types of red-green color blindness, including protanopia, deuteranopia, protanomaly, and deuteranomaly. Red-green color deficiency is the most common form of color blindness, affecting approximately 8% of men and 0.4% of women worldwide.