Search results
Results From The WOW.Com Content Network
Pseudoexfoliation syndrome, often abbreviated as PEX [1] and sometimes as PES or PXS, is an aging-related systemic disease manifesting itself primarily in the eyes which is characterized by the accumulation of microscopic granular amyloid-like protein fibers. [2]
A distant object is defined as an object located beyond 6 meters (20 feet) from the eye. [citation needed] When an object is located close to the eye, the rays of light from this object no longer approach the eye parallel to each other. Consequently, the eye must increase its refractive power to bring those rays of light together on the retina.
A pinhole occluder is an opaque disk with one or more small holes through it, used by ophthalmologists, orthoptists and optometrists to test visual acuity. The occluder is a simple way to focus light, as in a pinhole camera , temporarily removing the effects of refractive errors such as myopia .
For light to converge to a perfect point, the wavefront emerging from the optical system must be a perfect sphere centered on the image point. The distance in micrometers between the actual wavefront and the ideal wavefront is the wavefront aberration, which is the standard method of showing the aberrations of the eye.
Visual or vision impairment (VI or VIP) is the partial or total inability of visual perception.In the absence of treatment such as corrective eyewear, assistive devices, and medical treatment, visual impairment may cause the individual difficulties with normal daily tasks, including reading and walking. [6]
The eye develops in utero during the first three months of pregnancy, and a gap called the choroidal fissure appears at the bottom of the stalks that eventually form the eye, the AAO explains.
There is some confusion over how the focusing mechanism of the eye works. [clarification needed] In the 1977 book, Eye and Brain, [13] for example, the lens is said to be suspended by a membrane, the 'zonula', which holds it under tension. The tension is released, by contraction of the ciliary muscle, to allow the lens to become more round, for ...
Retinal tufts can be visualized or diagnosed using a dilated eye examination and indirect ophthalmoscope or a widefield retinal scan. [3] A retinal tuft is a gliotic degeneration of the retina composed of focal adhesions in the extracellular matrix joining the retina and the posterior hyaloid of the eye. [4] [5]