1. The clinical macula is smaller in area than the anatomical macula. The clinical macula appears as a small and fuzzy dark spot and can be distinguished through the pupil by clinical observation with an ophthalmoscope. The anatomical macula is not distinguishable through an ophthalmoscope as it is defined histologically; that is in terms of having two or more layers of ganglion cells. The anatomical macula is larger and encloses the clinical macula. 3. This would be the structural characteristic about midway between the fovea and far periphery, where rods are more numerous than cones and more photoreceptors are converging on bipolar cells. 4. There are three types of cones in our retinas. These three receptors each contain a different pigment. The pigments differ slightly in their chemical properties and subsequently in their relative ability to absorb light of different wavelengths. These cones are loosely called "blue", "green", and "red" as they are supposed reflect their peak sensitivities on …show more content…
In colour vision, the combination of two wavelengths can be exactly equivalent visually to a third wavelength. Such visual equivalences of stimuli that differ physically are called “metamers.” An example of a metamer in colour vision would be when the light of a wavelength that appears blue is added to one that appears yellow but the result appears white. Another example is a mixture of red and green wavelengths of light appearing yellow. Trichromacy explains metamers with its inherent idea that manipulating the three lights red, green and blue can produce any colour. Trichromacy theory supposes there are three cone types with different spectral sensitivities and that the perceived colour is determined by the cone output depending on the wavelengths of light absorbed from the image. If two physically different lights evoke the same responses in the 3 cones then the two lights will look the same (metamers). This is how trichromacy explains the existence of