It has been regarded that color perception is dependent on the specialized cells of the eye. This may no longer be true as the results of a research state that our perception of color is controlled much more by our brains than by our eyes.
The number of color-sensitive cones in the human retina differs dramatically among people—by up to 40 times—yet people appear to perceive colors the same way. The study has shown that color perception goes far beyond the hardware of the eye, and leads to a lot of interesting questions about how and why we perceive color.
The researchers have exploited a technology known as adaptive optics that was originally used by astronomers. This laser-based system maps out the topography of the inner eye in exquisite detail that would not have been possible otherwise.
The pigment that allows each cone in the human eye to react to different colors is very fragile. For the experiment, the researchers allowed light to shine directly into the eye to determine what wavelengths each cone reflects and absorbs, and thus to which color each is responsive.
Each subject was asked to tune the color of a disk of light to produce a pure yellow light that was neither reddish yellow nor greenish yellow. Everyone selected nearly the same wavelength of yellow, showing that all of them had the same perception regarding the yellow color. However, there was a considerable discrepancy when the retinal cells were examined. It was infact greater than a 40:1 ratio, even when all the cases were 'seeing' the same color yellow.
This finding throws light on the fact that everyone tested had the same color experience despite the difference in his or her visual system. It is therefore believed that some kind of normalization or some kind of circuit in the brain should be present to balance the observed difference.
These experiments show that color is defined by our experience in the world, and since we all share the same world, we arrive at the same definition of colors. The team has focused itself towards identification of a genetic basis for this large variation between retinas.
Medindia on Anatomy of eye:
The retina is the eye's sensitive layer that sends visual signals to the brain. To produce a sharp image, the lens must remain clear.