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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.
Perimetry or campimetry is one way to systematically test the visual field. [1] [failed verification] It is the systematic measurement of differential light sensitivity in the visual field by the detection of the presence of test targets on a defined background. Perimetry more carefully maps and quantifies the visual field, especially at the ...
Testing the visual fields consists of confrontation field testing in which each eye is tested separately to assess the extent of the peripheral field. Normal visual field of a right eye. To perform the test, the individual occludes one eye while fixated on the examiner's eye with the non-occluded eye.
Confrontation visual field testing is an important part of a routine ophthalmological or neurological examination. It can be used for rapid and gross assessment of large-scale visual field problems due to ophthalmological or neurological diseases, such as homonymous and heteronymous hemianopias, quadranopsia, altitudinal visual loss, central/centrocecal scotoma etc. [1] [2] Test using a red ...
Low vision visual acuity examinations are done using the LogMAR chart. The advantage that this presents with is that it allows for more accurate measures of the individual's vision to be recorded. Other tests done and their significance are as follows: Amsler's grid test - to locate scotomas on the visual field of the individual
The Snellen Chart demonstrates visual acuity by presenting standard Roman letters in a variety of sizes. The result of this test is a rough generalization of the acuity of a person based on the normal accepted acuity, such that a letter that subtends a visual angle of 5 minutes of an arc at 20 feet can be seen. To have 20/60 vision, for example ...
Visual acuity is a measure of how well small details are resolved in the very center of the visual field; it therefore does not indicate how larger patterns are recognized. Visual acuity alone thus cannot determine the overall quality of visual function. [8]
Microperimetry, sometimes called fundus-controlled perimetry, [1] is a type of visual field test [2] which uses one of several technologies to create a "retinal sensitivity map" of the quantity of light perceived in specific parts of the retina [3] in people who have lost the ability to fixate on an object or light source.