A few previous studies have examined the nature of this interaction. Studies that tested at the fovea found independence while studies that tested away from the fovea found interaction. Results from this project have shown significantly more interaction between color mechanisms away from the fovea, suggesting that models of visual processing based on fovea results may not be appropriate for nonfoveal vision. Studies of mechanisms of visual loss with aging. Vision changes with age have been well documented.
Recent evidence indicates that morphological changes occur in the retina with increasing age.
The hypothesis that yellow macular pigment protects the foveal area from light damage has been tested, and evidence has been found supporting this hypothesis, lending indirect evidence that light exposure throughout a lifetime contributes to retinal damage. Understanding rod monochromatism. Typical total color blindness, achromatopsia or rod monochromatism, is inherited as an automal recessive condition and is thought to result from absence of cone function. Rod monochromats have been used in basic visual studies as models of normal human rod vision and to study rod vision without interference from cone receptors. This was under the assumption that they only have rods, that their rods are like normal rods, and that rod-cone interaction is not important or doesn't exist.