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An epicanthic fold or epicanthus [6] is a skin fold of the upper eyelid that covers the inner corner (medial canthus) of the eye. [3] However, variation occurs in the nature of this feature and the possession of "partial epicanthic folds" or "slight epicanthic folds" is noted in the relevant literature.
In order, along the optic axis, the optical components consist of a first lens (the cornea—the clear part of the eye) that accounts for most of the optical power of the eye and accomplishes most of the focusing of light from the outside world; then an aperture (the pupil) in a diaphragm (the iris—the coloured part of the eye) that controls ...
In 2008 the rate of low birth weight was the highest in babies born to women younger than 15 years old (12.4%). [23] Women aged 40–54 had a rate of low birth weight at 11.8 percent. The lowest rates of low birth weight happened among babies whose mothers were between the ages of 25–29 years (4.4%) and 30–34 years (7.6%). [23]
At birth, visual structures are fully present yet immature in their potentials. From the first moment of life, there are a few innate components of an infant's visual system. Newborns can detect changes in brightness, distinguish between stationary and kinetic objects, as well as follow kinetic objects in their visual fields.
of or pertaining to the eye's pupil: Greek κόρη (kórē), girl, doll; pupil of the eye corectomy: cord(i)-of or pertaining to the heart (uncommon as a prefix) Latin cor, heart commotio cordis, cornu-applied to describing processes and parts of the body as likened or similar to horns Latin cornū, horn greater cornu: coron-pertaining to the ...
Several layers such as the neural tube, neural crest, surface ectoderm, and mesoderm contribute to the development of the eye. [2] [3] [4] Eye development is initiated by the master control gene PAX6, a homeobox gene with known homologues in humans (aniridia), mice (small eye), and Drosophila (eyeless). The PAX6 gene locus is a transcription ...
[1] [2] [3] Macrosomia is a similar term that describes excessive birth weight, but refers to an absolute measurement, regardless of gestational age. [4] Typically the threshold for diagnosing macrosomia is a body weight between 4,000 and 4,500 grams (8 lb 13 oz and 9 lb 15 oz), or more, measured at birth, but there are difficulties reaching a ...
The rate of eye evolution is difficult to estimate because the fossil record, particularly of the lower Cambrian, is poor. How fast a circular patch of photoreceptor cells can evolve into a fully functional vertebrate eye has been estimated based on rates of mutation, relative advantage to the organism, and natural selection.