Classes
Most vertebrates have several different classes of cone cells, differentiated primarily by the specific photopsin expressed within. The number of cone classes determines the degree of color vision. Vertebrates with one, two, three or four classes of cones possess monochromacy, dichromacy, trichromacy and tetrachromacy, respectively.
Humans normally have three classes of cones, designated L, M and S for the long, medium and short wavelengths of the visible spectrum to which they are most sensitive.[7] L cones respond most strongly to light of the longer red wavelengths, peaking at about 560 nm. M cones, respond most strongly to yellow to green medium-wavelength light, peaking at 530 nm. S cones respond most strongly to blue short-wavelength light, peaking at 420 nm, and make up only around 2% of the cones in the human retina. The peak wavelengths of L, M, and S cones occur in the ranges of 564–580 nm, 534–545 nm, and 420–440 nm, respectively, depending on the individual.[citation needed] The typical human photopsins are coded for by the genes OPN1LW, OPN1MW, and OPN1SW. The LMS color space is an often-used model of spectral sensitivities of the three cells of a typical human.[8][9]
Histology
The structure of a cone cell
Cone cells are shorter but wider than rod cells. They are typically 40–50 μm long, and their diameter varies from 0.5–4.0 μm. They are narrowest at the fovea, where they are the most tightly packed. The S cone spacing is slightly larger than the others.[10]
Like rods, each cone cell has a synaptic terminal, inner and outer segments, as well as an interior nucleus and various mitochondria. The synaptic terminal forms a synapse with a neuron bipolar cell. The inner and outer segments are connected by a cilium.[2] The inner segment contains organelles and the cell's nucleus, while the outer segment contains the light-absorbing photopsins, and is shaped like a cone, giving the cell its name.[2]
The outer segments of cones have invaginations of their cell membranes that create stacks of membranous disks. Photopigments exist as transmembrane proteins within these disks, which provide more surface area for light to affect the pigments. In cones, these disks are attached to the outer membrane, whereas they are pinched off and exist separately in rods. Neither rods nor cones divide, but their membranous disks wear out and are worn off at the end of the outer segment, to be consumed and recycled by phagocytic cells.
Distribution
Illustration of the distribution of cone cells in the fovea of an individual with normal color vision (left), and a color blind (protanopic) retina. Note that the center of the fovea holds very few blue-sensitive cones.
Distribution of rods and cones along a line passing through the fovea and the blind spot of a human eye[11]
While rods outnumber cones in most parts of the retina, the fovea, responsible for sharp central vision, consists almost entirely of cones. The distribution of photoreceptors in the retina is called the retinal mosaic, which can be determined using photobleaching. This is done by exposing dark-adapted retina to a certain wavelength of light that paralyzes the particular type of cone sensitive to that wavelength for up to thirty minutes from being able to dark-adapt, making it appear white in contrast to the grey dark-adapted cones when a picture of the retina is taken. The results illustrate that S cones are randomly placed and appear much less frequently than the M and L cones. The ratio of M and L cones varies greatly among different people with regular vision (e.g. values of 75.8% L with 20.0% M versus 50.6% L with 44.2% M in two male subjects).[12]
GPS World +2
)
P.S. I wish you everything that science has to offer to help you with your eyesight. 
Science is amazing when it works, and I have never said otherwise.
