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Blue eyes are a highly sexually dimorphic eye color. Studies from various populations in Europe have shown that men are substantially more likely to have blue eyes than women. [18] The inheritance pattern followed by blue eyes was previously assumed to be a Mendelian recessive trait, though this has been
Peak spectral sensitivities are in the blue region of the visible spectrum (near 440 nm). People with this condition generally show nystagmus ("jiggling eyes"), photophobia (light sensitivity), reduced visual acuity, and myopia (nearsightedness). [30] Visual acuity usually falls to the 20/50 to 20/400 range.
The inheritance pattern followed by blue eyes was previously assumed to be a mendelian recessive trait, however, eye color inheritance is now recognized as a polygenic trait, meaning that it is controlled by the interactions of several genes. [56] Blue eyes are predominant in northern and eastern Europe, particularly around the Baltic Sea.
Albinism is a congenital condition characterized in humans by the partial or complete absence of pigment in the skin, hair and eyes. Albinism is associated with a number of vision defects, such as photophobia, nystagmus, and amblyopia. Lack of skin pigmentation makes for more susceptibility to sunburn and skin cancers.
According to CNN, Dr. Gary Heiting, a licensed optometrist and senior editor of All About Vision explained why all human eyes are actually brown, no matter if they look blue or greenish.
Melanin is responsible for giving color to the skin, hair, and eyes. Moreover, melanin is found in the light-sensitive tissue of the retina of the eye which plays a role in normal vision. The exact function of protein P is unknown, but it has been found that it is essential for the normal coloring of skin , eyes , and hair ; and likely involved ...
Oculocutaneous albinism is a form of albinism involving the eyes , the skin (-cutaneous), and the hair. [1] Overall, an estimated 1 in 20,000 people worldwide are born with oculocutaneous albinism. [1] OCA is caused by mutations in several genes that control the synthesis of melanin within the melanocytes. [2]
The ancestral allele is linked to darker pigmentation and dominant over the lighter pigment recessive allele. [10] [11] The rs12913832 SNP, located in intron 86 of the HERC2 gene contains a silencing sequence that can inhibit the expression of OCA2 and, if both recessive alleles are present, can homozygously cause blue eyes. [12]