Search results
Results From The WOW.Com Content Network
Visual acuity. For most people, the closest comfortable viewing distance, termed the near distance for distinct vision, [7] is approximately 25 cm. At this distance, a person with good vision can usually distinguish an image resolution of 5 line pairs per millimeter (lp/mm), equivalent to a CoC of 0.2 mm in the final image. Viewing conditions.
Eye examination for visual acuity. Visual acuity is a measure of the spatial resolution of the visual processing system. VA, as it is sometimes referred to by optical professionals, is tested by requiring the person whose vision is being tested to identify so-called optotypes – stylized letters, Landolt rings, pediatric symbols, symbols for the illiterate, standardized Cyrillic letters in ...
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.
An example of the Landolt C eye chart (also known as the Japanese eye chart.). Numerous types of eye charts exist and are used in various situations. For example, the Snellen chart is designed for use at 6 meters or 20 feet, and is thus appropriate for testing distance vision, while the ETDRS chart is designed for use at 4 meters. [16]
Too much video game playing may cause vision problems. [11] Extensive viewing of the screen can cause eye strain, as the cornea, pupil, and iris are not intended for mass viewing sessions of electronic devices. Using video games for too long may also cause headaches, dizziness, and chances of vomiting from focusing on a screen.
Visual acuity with Distant chart with correctors Visual acuity with eye chart at Distant 20 feet (6 m) and with (cc: Latin cum correctore) correctors (spectacles); Dsc is without (sc: Latin sine correctore) correctors. See Visual_acuity#Legal_definitions: VA Nsc - VA Ncc Visual acuity with Near chart without correctors
A phosphene is the perception of light without light actually entering the eye, for instance caused by pressure applied to the closed eyes. A phenomenon that could be entoptical if the eyelashes are considered to be part of the eye is seeing light diffracted through the eyelashes.
Specifically, to count as a legitimate view, a user must intentionally initiate the playback of the video and play at least 30 seconds of the video (or the entire video for shorter videos). Additionally, while replays count as views, there is a limit of 4 or 5 views per IP address during a 24-hour period, after which point, no further views ...