Macula of retina is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. The anatomical macula is defined histologically in terms of having two or more layers of ganglion cells. The umbo is the center of the foveola which in turn is located at the center of the fovea. The fovea is located near the center of the macula. It is a small pit that contains the largest concentration of cone cells. The retina contains two types of photosensitive cells, the rod cells and the cone cells. Because the macula is yellow in colour it absorbs excess blue and ultraviolet
Gene therapy for color blindness of 2018 there is no medical entity offering this treatment, and no clinical trials available for volunteers. The retina of the human eye contains photoreceptive cells called cones that allow color vision. A normal trichromat individual possesses three different types of cones to distinguish different colors within the visible spectrum from 380 nm to 740 nm. The three types of cones are designated L, M, and S cones, and each type is sensitive to a certain range of wavelength of light depending on what photopigment it contains. More specifically, the L cone absorbs around 560 nm, the M cone absorbs