the child’s age, comprehension, and communica-
tion abilities.
Sudden loss of vision in one eye or both
eyes is an emergency that requires
immediate medical care.Adults are generally able to perceive symptoms
of vision impairment, though when onset is grad-
ual the symptoms are less obvious (though may be
more apparent to co-workers, friends, and family
members). Sometimes the first indication of a seri-
ous vision impairment comes with a misfortune
such as a motor vehicle accident, especially among
older adults who do not notice or do not acknowl-
edge diminishing vision. Symptoms of vision
impairment include
- dimness or changes in color perception
- need to hold objects closer or farther away
from eyes - frequent headaches or squinting
- loss of sharpness or clarity of vision
- difficulty reading
- difficulty seeing at night or in low light
- the need for bright lighting
The diagnostic path includes a comprehensive
ophthalmic examination to assess visual acuity,
visual field, and refractive error as symptoms indi-
cate. Further diagnostic procedures may be neces-
sary when the underlying cause of vision
impairment appears to be a health condition other
than a problem with the eyes, such as MULTIPLE
SCLEROSISor DIABETES.
COMMON CAUSES OF VISION IMPAIRMENT
AGE-RELATED MACULAR ALBINISM
DEGENERATION(ARMD) CATARACT
AMBLYOPIA congenital
central serous RETINOPATHY CYTOMEGALOVIRUS(CMV)
congenital disorders corneal deterioration
GENETIC DISORDERS GLAUCOMA
INFECTION MULTIPLE SCLEROSIS
RETINAL DETACHMENT RETINOBLASTOMA
retinopathy ofDIABETES retinopathy of HYPERTENSION
retinopathy of prematurity STROKE
TRAUMA TO THE EYE uncorrectableMYOPIA
Treatment Options and Outlook
Treatment depends on the cause of the VISION
IMPAIRMENT. CORRECTIVE LENSESor REFRACTIVE SUR-
GERYtypically improve vision in conditions such as
severe MYOPIAor ASTIGMATISM, even if these meas-
ures cannot fully restore normal vision. Surgery is
often the solution for vision impairment due to
CATARACT, CORNEAL INJURYor deterioration, RETINAL
DETACHMENT, and some forms of GLAUCOMA. Med-
ications can control other forms of glaucoma.
Vision impairment has a significant effect on
QUALITY OF LIFE. There are numerous assistive
devices for people who have functional limitations
as a result of vision impairment. Most people who
have vision impairments are able to participate,
with reasonable accommodations and sometimes
creative effort, in work and recreational activities
they enjoy. Continued advances in technology
generate new treatment approaches that may
offer improved vision.Risk Factors and Preventive Measures
Many health conditions can contribute to or cause
vision impairment. The most significant are dia-
betes, HYPERTENSION, and glaucoma. Early diagnosis
and appropriate treatment can limit or prevent
damage to the eyes and to vision. Eye protection,
such as sunglasses and safety eyewear for activities
with risk for impact or debris, is a key preventive
measure. More than 40,000 preventable eye
injuries occur every year. Routine ophthalmic
examinations detect eye problems early, allowing
for the most appropriate and effective interven-
tions to preserve vision.
See also BRAILLE; COLOR DEFICIENCY; HEADACHE;
MOTOR VEHICLE ADDIDENTS; VISION HEALTH.vitrectomy An OPERATIONto remove the vitreous
humor from within the EYEas treatment for RETI-
NAL DETACHMENT, vitreous HEMORRHAGE (bleeding
into the vitreous humor), RETINOPATHY, and foreign
body penetration. In vitrectomy, the ophthalmolo-
gist makes three tiny incisions in the sclera (white
portion) of the eye for the insertion of a cutting
instrument, a light, and an infusion tube. The cut-
ting instrument rotates to gently pull the vitreous
humor out of the eye, and the ophthalmologist
replaces it with a saline-based solution at the same
rate to maintain pressure and stability within thevitrectomy 123