There was a time when people with low vision thought

by:Sinowon     2020-06-17
Currently, Some countries like the US, permit people with mild to moderate levels of central vision loss - but with intact peripheral vision - apply for driving privileges when using a bio optic lens system, after completion of formalized low vision driver education training. These are spectacle - mounted telescopes that can be pre-made or can be custom-fit given a patient's eyeglass prescription in the telescope. Henry Greene, Co-founder of US-based Ocutech, which has bio optic telescopes, says that by attaching bio optic telescope to Optical Lenses, the user can switch their sight between their 'regular vision' and the 'magnified vision' offered by the telescope by slightly tilting their head downward, since the telescopes are usually angled upward. For instance, when the user is walking on a pavement and wants to see a tilt his head down while looking straight ahead to view a magnified image through the telescope. There are other companies too that offer a variety of such telescopes including monocular and binocular, focusable and fixed-focus, Galilean and Keplerian designs, hand-held and spectacle mounted, in a diverse range of magnifications. According to Eschenbach, another manufacturer of Bio Optic devices, any task distance (near, intermediate, far away) and any task duration (short - term or long -term). A child with low vision may experience difficulty in acquiring concepts. Vision is an organizing sense that allows us to perceive objects at a distance and to make connections between these objects. Many concepts developed in childhood are learned incidentally through vision. If the visual sense is impaired, concepts may be incompletely developed or missed entirely. Because of this, it is important for children with low vision to directly experience as much of their world as possible and to receive augmented instruction in making connections between objects and processes. Much confusion exists in the terminology surrounding low vision. Often times, individuals may use the terms partially sighted, legally blind, blind, and low vision interchangeably. Although out of date, the term partially sighted refers to individuals with visual acuities ranging from 20/70 to 20/200. For example, a student with acuity of 20/100 is able to see at 20 feet what an individual with 20/20 visual acuity sees at 100 feet. Legal blindness refers to individuals with central visual acuities of 20/200 or less in the better eye with the best possible correction, or with visual fields of 20 degrees or less. Blindness is a more general term used to describe a person with a significant loss of vision, usually in the range of 20/200 or less. Often times, the term is used to explain an individual with very little or no functional use of vision. Low vision is a term related not only to visual acuity but often includes an individual's level of visual functioning. A precise definition for an individual with a visual impairment who is not functionally blind is an individual who has 'difficulty accomplishing visual tasks, even with prescribed corrective lenses, but who can enhance his or her ability to accomplish these tasks with the use of compensatory visual strategies, low vision and other devices, and environmental modifications' (Corn and Koenig, 1996).
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