Visual acuity is considered one of the vital signs of the eye and is measured at a predetermined distance, often using a Snellen chart.
Visual acuity refers to clarity or sharpness of vision.
Impaired visual acuity is associated with decreased function quality-of-life, increased falls and other accidental injuries.
Impaired visual acuity is underreported or unrecognized in the elderly because vision changes can be subtle, progress very slowly, or occur when n persons with cognitive impairment.
The Snellen chart has a non–geometric progression of letter-size and variable number of letters use per line.
The Snellen chart is insufficiently standardized and the retro illuminated logMAR chart is used to measure visual acuity in perspective clinical research.
Impaired visual acuity in about 12% US adults aged 65-74 years, and 15% or older despite glasses or contact lenses.
Older adults have higher prevalence of ocular disease and systemic diseases associated with ocular disease than younger adults.
Refractive error, age-related macula degeneration and cataracts are common causes of impaired visual acuity in older adults.
Estimated 6% US adults age 50-54 years have severe refractive error, as does 15% adults age 65-69 years, and 20% of adults 80 years or older.
About 60% of cases of refractive error can be corrected to >20/40 visual acuity.
More than 3.8 million adults older than 45years in the US are estimated to have low vision.
Impaired vision is associated with decreased quality-of-life, increased depression, falls, and mortality.
The USPST has concluded that the current evidence is insufficient to assess the balance of benefits in harms of screening for impaired visual acuity in asymptomatic older results.