Ad
related to: common visual field defects
Search results
Results from the WOW.Com Content Network
Measurements of visual field defects can be done by visual field testing. It can be performed by various methods, including confrontation technique, amsler grid, tangent screen, kinetic perimetry, or static perimetry. Cost common is automated perimetry.
Central visual acuity of 20/200 or less in the better eye with corrective glasses or central visual acuity of more than 20/200 if there is a visual field defect in which the peripheral field is contracted to such an extent that the widest diameter of the visual field subtends an angular distance no greater than 20 degrees in the better eye. [22]
Hemianopsia, or hemianopia, is a visual field loss on the left or right side of the vertical midline. It can affect one eye but usually affects both eyes. Homonymous hemianopsia (or homonymous hemianopia) is hemianopic visual field loss on the same side of both eyes. Homonymous hemianopsia occurs because the right half of the brain has visual ...
Lesions in the pathway cause a variety of visual field defects. The type of field defect can help localize where the lesion is located (see figure). A lesion in the optic nerve of one eye causes partial or complete loss of vision in the same eye, with an intact field of vision in other eye.
The visual field of each eye can be divided in two vertically, with the outer half being described as temporal, and the inner half being described as nasal. "Bitemporal hemianopsia" can be broken down as follows: bi-: involves both left and right visual fields; temporal: involves the temporal visual field; hemi-: involves half of each visual field
It is a diagnostic tool that aids in the detection of visual disturbances caused by changes in the retina, particularly the macula (e.g. macular degeneration, Epiretinal membrane), as well as the optic nerve and the visual pathway to the brain. Amsler grid usually help detecting defects in central 20 degrees of the visual field. [2]
Binasal (either inferior or superior) quadrantanopia, also known as Nerurkarian field defects affects either the upper or lower inner visual quadrants closer to the nasal cavity in both eyes. Bitemporal (either inferior or superior) quadrantanopia affects either the upper or lower outer visual quadrants in both eyes. [citation needed]
The most common visual field defects include an enlarged blind spot and a scotoma. Visual acuity is typically not affected by the pit but may get worse if serous detachment of the macula occurs. Metamorphopsia (distorted vision) may then result. Optic pits were first described in 1882 as dark gray depressions in the optic disc. [1]
Ad
related to: common visual field defects