PRELIMS Flashcards
‘Educationally, legally, functionally’
- Often used to indicate visual impairment requiring specialist services or financial
assistance
- Carries the perception that ‘all sight is gone
BLIND
A person one who has impairment of visual function for whom full
remediation is not possible by conventional spectacles, contact lenses or medical
intervention and which causes restriction in that person’s everyday life
Low Vision
Broader spectrum of sight loss
- ‘Partial sight, low vision, subnormal vision’
Visual Impairmen
In 1950s and 1960, it was defined as visual acuity of 20/70 or worse with the best
conventional optical correction
Subnormal Vision
In 1975, defined as reduced central acuity or visual field loss which, even with the best
optical correction provided by regular lenses, still results in visual impairment
Low Vision
one of the major problems to collect data was non-standardization of definition. Around
65 different types of definitions were used worldwide to describe the definition of blindness and
poor vision
1973
low vision was defined as reduced visual acuity by disorder of the eye or visual system. A
level of vision which cannot be improved to within normal limits by medication, surgery, or use
of conventional correction.
1976
WHO proposed a standard classification that would be used worldwide. This was included
in 10th revision of the International Classification of Diseases (ICD-10) but unfortunately this
classification is not accepted worldwide although references to it are now common.
1978
WHO offered a new definition of Low Vision
1992
Refers to conditions encompassing the continuum from partial sight to blindness.
VIDION IMPAIRMENT
defined as visual acuity less than 3/60 in the better eye after best possible correction and
visual field < 10 degree from the point of fixation.
Blindness
is defined as visual acuity 3/60 (20/400) to less than 6/18 (20/70) in the better eye after
best possible correction in the better eye and visual field <20 degree from the point of
fixation.
WHO definition of Low Vision
refers to an individual’s functional visual ability in spite of loss, how an individual develops
creative ways of adapting to various situations. The use of low vision aids increases visual
efficiency. It depends on training, experience, intelligence level, and personality
characteristics of the individual, as well as other disabilities that may interfere with normal
function.
Visual Efficiency
the international standard diagnostic classification for all general epidemiological, many
health managements purposes and clinical use.
- It is used to classify diseases and other health problems recorded on many types of health
and vital records including death certificates and health records.
International Classification of Disease
It gives rise to anatomical changes in the visual organs
- For example, Glaucoma in its early stages can go unnoticed by the patient, without
affecting abilities
Visual Disorder
Functional loss from a visual disorder.
- It affects visual acuity, visual field, color vision, contrast sensitivity
Visual Impairment
It gives rise to vision-related changes in the skill and abilities
- It is measured in terms of the skills - can or cannot perform.
Visual Disability
It has psychosocial and economic consequences of visual loss.
- Skills of the person gets hampered
- Giving rise to barriers in the environment both physical and social.
Visual Handicap
Who are the Low Vision patients?
Patients with congenital eye diseases and diseases occurring early in life
2. Patients with degenerative diseases occurring later in life
Persons with such condition may indicate a diminution of vision, haziness, or foggy
vision.
Lower central acuity or fluctuating vision
