The Claim
As macular pigment optical density increases from near zero to 1.0 log units, the orientation of the red-green color discrimination ellipse shifts systematically from approximately 75° to 55°.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
When the amount of macular pigment in the eye increases from low to high levels, the direction in which people best distinguish red from green colors changes from about 75 degrees to 55 degrees.
See the scientific wording
The orientation of the red-green color discrimination ellipse shifts systematically from approximately 75° to 55° as macular pigment optical density increases from near zero to 1.0 log units, suggesting that macular pigment may alter the axis of maximal chromatic sensitivity in red-green vision.
Yellow pigment in the center of the eye blocks blue light, which reduces activity in the blue-sensitive cells. This makes the red and green cells compare their signals more clearly, so the eye becomes better at spotting small differences between red and green, and the direction it’s most sensitive to shifts from blue-yellow toward red-green.
What the research says
1 studyStudy: Effect of macular pigment optical density on Yellow‐Blue and Red‐Green colour discrimination
When there's more yellow pigment in the center of the eye, people get better at spotting tiny differences between red and green, and the direction they're best at seeing these colors shifts slightly — from more blue-yellow toward more red-green. The study measured this and found it really happens.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.