Accommodation:
The mechanism by which the eye can focus very quickly
on an object and see it clearly at any distance. This
ability decreases with age.
Animation illustrating accomodation.
From Godeau's the Traité de Médecine; accommodation
to focus on a book as it moves away or comes closer.
Visual
acuity
It is defined as the smallest angle at which the eye
can tell two distinct points apart and is usually considered
a measure of eye performance. In fact, visual acuity
is only one of the three dimensions of HEALTHY VISION,
along with VISUAL COMFORT and the absence of GLARE.
Cataract
Cataracts cause 40% of all cases of blindness and are
in fact the leading cause of blindness in the world.
A cataract is a clouding of the lens that causes progressive
loss of vision and can be treated surgically. Cataract
surgery is very common in developed countries.
.
Visual field
The visual field is the area in which a person can see
without turning his or her head.
Certain neurological diseases may reduce the visual
field.
Visual comfort
Visual comfort is the visual well-being that makes the
act of seeing easy, pleasant, and comfortable in any
environment and under any circumstances. Visual comfort
is one of the dimensions of HEALTHY VISION.
True visual comfort means seeing without thinking or
needing to modify the viewing angle to avoid glare,
and without having to strain to make a distant object
clearly.
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