New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Eye examination

An eye examination is a battery of tests performed by an ophthalmologist or optometrist assessing vision and ability to focus on and discern objects, as well as other tests and examinations pertaining to the eyes. All people should have periodic and thorough eye examinations as part of routine care by the primary care physician, especially since many eye diseases are silent or asymptomatic.

Eye examinations may detect potentially treatable blinding eye diseases, ocular manifestations of systemic disease, or signs of tumours or other anomalies of the brain. Visual acuity is the eye's ability to detect fine details and is the quantitative measure of the eye's ability to see an in-focus image at a certain distance. The standard definition of normal visual acuity (20/20 or 6/6 vision) is the ability to resolve a spatial pattern separated by a visual angle of one minute of arc. The terms 20/20 and 6/6 are derived from standardized sized objects that can be seen by a "person of normal vision" at the specified distance. For example, if one can see the normal object that can usually be seen at 20 ft at a distance of 20 ft, then you have 20/20. If one can see at 20 ft what a normal person can see at 40 ft, then the vision is 20/40. Similarly, if one can see at 20 ft an object size that normally can be seen at 200 ft, then the vision is 20/200.

Related Stories
 


Health & Medicine News

August 27, 2025

Researchers propose that the U.S. could safely drop adult tetanus and diphtheria boosters, saving $1 billion annually, since childhood vaccinations provide decades of protection. Evidence from the ...
Scientists at Kyoto University have uncovered a hidden protein complex that organizes DNA in sperm stem cells, a discovery that reveals surprising ties between fertility and cancer. When this protein, called STAG3, is missing, sperm stem cells ...
University of Minnesota researchers developed a 3D-printed scaffold that directs stem cells to grow into functioning nerve cells, successfully restoring movement in rats with severed spinal cords. This promising technique could transform future ...
Scientists have cracked one of chemistry’s toughest challenges with indoles, using copper to unlock a spot once thought too stubborn to change. The discovery could pave the way for easier, cheaper ...
Knee osteoarthritis is a major cause of pain and disability, but routine X-rays often do more harm than good. New research shows that being shown an X-ray can increase anxiety, make people fear exercise, and lead them to believe surgery is the only ...
A nationwide study found that recent colds caused by rhinoviruses can give short-term protection against COVID-19. Children benefit most, as their immune systems react strongly with antiviral defenses, helping explain their lower rates of severe ...
Australian teachers are in crisis, with 9 in 10 experiencing severe stress and nearly 70% saying their workload is unmanageable. A major UNSW Sydney study found teachers suffer depression, anxiety, and stress at rates three to four times higher than ...
Painkillers we often trust — ibuprofen and acetaminophen — may be quietly accelerating one of the world’s greatest health crises: antibiotic resistance. Researchers discovered that these drugs not only fuel bacterial resistance on their own ...
Researchers uncovered that the Maui wildfires caused a spike in deaths far higher than reported, with hidden fatalities linked to fire, smoke, and lack of medical access. They warn that prevention rooted in Native Hawaiian ecological knowledge is ...
Living near the ocean may actually help you live longer. A new nationwide study found that people in coastal regions enjoy life expectancies a year or more above the U.S. average, while city dwellers near inland rivers and lakes may face shorter ...
A large study of nearly 16,000 adults found no link between eating animal protein and higher death risk. Surprisingly, higher animal protein intake was associated with lower cancer mortality, supporting its role in a balanced, health-promoting ...
Scientists have identified compounds that block bitter taste receptors activated by saccharin and acesulfame K. The most promising is (R)-(-)-carvone, which reduces bitterness without the cooling side effect of menthol, potentially making sugar-free ...

Latest Headlines

updated 12:56 pm ET