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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.
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 ...
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 ...
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.
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]
Swiss ophthalmologist Marc Amsler described the Amsler grid in the year 1945. It was the first functional test proposed to evaluate metamorphopsia. [4] He may have gotten the idea of the grid from Edmund Landolt, who used a similar small card with a grid pattern to be kept in the center of the visual field testing instrument perimeter. [3]
Confrontation visual field testing is a simple and quick visual field assessing method. A confrontational field test requires little or no special equipment and can be performed in any room, which is well illuminated. Patient sitting straight in front of the examiner, is asked look directly at the examiner's eye during the test.
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.