Search results
Results from the WOW.Com Content Network
The size of the smallest optotypes that can be reliably identified is considered the person's visual acuity. The Snellen chart is the most widely used. Alternative types of eye charts include the logMAR chart, Landolt C, E chart, Lea test, Golovin–Sivtsev table, the Rosenbaum chart, and the Jaeger chart.
Near visual acuity or near vision is a measure of how clearly a person can see nearby small objects or letters.Visual acuity in general usually refers clarity of distance vision, and is measured using eye charts like Snellen chart, LogMAR chart etc. Near vision is usually measured and recorded using a printed hand-held card containing different sized paragraphs, words, letters or symbols.
Some clinics do not have 6-metre eye lanes available, and either a half-size chart subtending the same angles at 3 metres (9.8 ft), or a reversed chart projected and viewed by a mirror is used to achieve the correct sized letters. In the most familiar acuity test, a Snellen chart is placed at a standard distance: 6 metres.
The pupil of the human eye can range in size from 2 mm to over 8 mm to adapt to the environment The human eye can detect a luminance from 10 −6 cd/m 2 , or one millionth (0.000001) of a candela per square meter to 10 8 cd/m 2 or one hundred million (100,000,000) candelas per square meter.
Pupils of both sexes dilated after seeing pictures of people of the opposite sex. In females, the difference in pupil size occurred also after seeing pictures of babies and mothers with babies. This examination showed that pupils react not only to the changes of intensity of light (pupillary light reflex) but also reflect arousal or emotions.
In 2020, Trump pardoned the elder Kushner for convictions from 2005 over tax fraud, retaliating against a witness who testified against him and making false statements to the Federal Election ...
How can you tell if they’re safe past their expiration dates? Here, doctors explain how long most vitamins last and any risks associated with taking expired vitamins.
The Jaeger chart is an eye chart used in testing near visual acuity. It is a card on which paragraphs of text are printed, with the text sizes increasing from 0.37 mm to 2.5 mm. [ 1 ] This card is to be held by a patient at a fixed distance from the eye dependent on the J size being read.