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The eyes of people with severe forms of albinism may appear red under certain lighting conditions owing to the extremely low quantities of melanin, [71] allowing the blood vessels to show through. In addition, flash photography can sometimes cause a " red-eye effect ", in which the very bright light from a flash reflects off the retina, which ...
In humans, melanin is the primary determinant of skin color. It is also found in hair, the pigmented tissue underlying the iris of the eye, and the stria vascularis of the inner ear. In the brain, tissues with melanin include the medulla and pigment-bearing neurons within areas of the brainstem, such as the locus coeruleus.
It is due to excess production of melanin in the setting of a normal number of melanocytes in the conjunctiva. It appears very early in life and the pattern does not seem to change upon reaching adulthood. There can be asymmetrical involvement of the eyes, and lesions are usually described as flat, brown, and patchy areas of pigmentation. [3]
More melanin means darker eyes, hair or skin. The color of the melanin in the eyes is determined by three other genes, EYCL1, 2 and 3. Together, they account for brown, green and blue, but not ...
It is caused by melanocyte or melanin depletion, or a decrease in the amino acid tyrosine, which is used by melanocytes to make melanin. [2] Some common genetic causes include mutations in the tyrosinase gene or OCA2 gene. [3] [4] As melanin pigments tend to be in the skin, eye, and hair, these are the commonly affected areas in those with ...
Melanocytes are melanin-producing neural crest-derived [3] cells located in the bottom layer (the stratum basale) of the skin's epidermis, the middle layer of the eye (the uvea), [4] the inner ear, [5] vaginal epithelium, [6] meninges, [7] bones, [8] and heart found in many mammals and birds. [9] Melanin is a dark pigment primarily responsible ...
Central heterochromia is also an eye condition where there are two colors in the same iris; but the arrangement is concentric, rather than sectoral. The central (pupillary) zone of the iris is a different color than the mid-peripheral (ciliary) zone. Central heterochromia is more noticeable in irises containing low amounts of melanin. [32]
The human eye is a sensory organ in the visual system that reacts to visible light allowing eyesight. ... (which has a low or moderate concentration of melanin) ...