Search results
Results From The WOW.Com Content Network
Figure 1 - Humphrey field analyser. Humphrey field analyser (HFA) is a tool for measuring the human visual field that is commonly used by optometrists, orthoptists and ophthalmologists, particularly for detecting monocular visual field. [1] The results of the analyser identify the type of vision defect.
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 ...
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]
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.
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.
Manual hand eye test in Ghana (2018) Visual acuity is measured by a psychophysical procedure and as such relates the physical characteristics of a stimulus to a subject's percept and their resulting responses. Measurement can be taken by using an eye chart invented by Ferdinand Monoyer, by optical instruments, or by computerized tests [11] like ...
An eye chart is a chart used to measure visual acuity comprising lines of optotypes in ranges of sizes. Optotypes are the letters or symbols shown on an eye chart. [ 1 ] Eye charts are often used by health care professionals, such as optometrists , physicians and nurses , to screen persons for vision impairment .
An eye examination, commonly known as an eye test, [1] is a series of tests performed to assess vision and ability to focus on and discern objects. [2] It also includes other tests and examinations of the eyes. [2] Eye examinations are primarily performed by an optometrist, ophthalmologist, or an orthoptist.