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2. Eye chart - Wikipedia

   en.wikipedia.org/wiki/Eye_chart

   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]

3. Near visual acuity - Wikipedia

   en.wikipedia.org/wiki/Near_visual_acuity

   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.

4. Amsler grid - Wikipedia

   en.wikipedia.org/wiki/Amsler_grid

   Amsler grid, Chart 1. There are 7 types of Amsler grid charts. All charts measure 10 cm × 10 cm (3.9 in × 3.9 in), which when viewed at a distance of 33 cm (13 in) from the eye can be used to measure defects in the central 20 degrees of the visual field. [3]

5. Snellen chart - Wikipedia

   en.wikipedia.org/wiki/Snellen_chart

   A person taking the test covers one eye from 6 metres or 20 feet away, and reads aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the visual acuity in that specific eye. The symbols on an acuity chart are formally known as "optotypes". Variation of Snellen chart with another letter ...

6. Visual field test - Wikipedia

   en.wikipedia.org/wiki/Visual_field_test

   A visual field test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions such as glaucoma, stroke, pituitary disease, brain tumours or other neurological deficits.

7. List of instruments used in ophthalmology - Wikipedia

   en.wikipedia.org/wiki/List_of_instruments_used...

   to test colour vision ••Ishihara's chart: to determine the type of colour blindness Stenopaeic slit: detection of axis of the cylindrical (astigmatism) power of the eye; glaucoma testing Implants - •Intraocular lens: prosthetic lenses implanted after lens (anatomy) removal •Artificial eyes: as non-functional cosmetic implants into the ...