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Retinal hemorrhage (UK English: retinal haemorrhage) is a disorder of the eye in which bleeding occurs in the retina, the light sensitive tissue, located on the back wall of the eye. [1] There are photoreceptor cells in the retina called rods and cones , which transduce light energy into nerve signals that can be processed by the brain to form ...
Farther back still is the inner segment, a specialized part of the cell full of mitochondria. The chief function of the inner segment is to provide ATP (energy) for the sodium-potassium pump . Finally, closest to the brain (and farthest from the field of view) is the outer segment, the part of the photoreceptor that absorbs light .
A subconjunctival hemorrhage can often occur without any obvious cause or harm to the eye. A strong enough sneeze or cough can cause a blood vessel in the eye to burst. Hyphema is a result of blunt or penetrating trauma to the orbit that increases intraocular pressure, causing tears in the vessels of the ciliary body and iris.
The human eye can function from very dark to very bright levels of light; its sensing capabilities reach across nine orders of magnitude. This means that the brightest and the darkest light signal that the eye can sense are a factor of roughly 1,000,000,000 apart. However, in any given moment of time, the eye can only sense a contrast ratio of ...
The inner segment contains organelles and the cell's nucleus, while the rod outer segment (abbreviated to ROS), which is pointed toward the back of the eye, contains the light-absorbing materials. [3] A human rod cell is about 2 microns in diameter and 100 microns long. [5]
Blue light, a type of high-energy light, is part of the visible light spectrum. High-energy visible light (HEV light) is short-wave light in the violet/blue band from 400 to 450 nm in the visible spectrum, which has a number of purported negative biological effects, namely on circadian rhythm and retinal health (blue-light hazard), which can lead to age-related macular degeneration.
Dr. Eddie Rodriguez, one of James' doctors for the transplant, previously said he was in "bad shape. They have to amputate his arm [above the elbow], so right at the midarm. His face is destroyed."
Hemostasis occurs when blood is present outside of the body or blood vessels. It is the innate response for the body to stop bleeding and loss of blood. During hemostasis three steps occur in a rapid sequence. Vascular spasm is the first response as the blood vessels constrict to allow less blood to be lost.