synfält

Synfält, or visual field, is the portion of space that can be seen when the eye fixes gaze on a central point. It encompasses central vision, which provides detail and color, and peripheral vision, which detects motion and spatial orientation. The visual field is defined for each eye, and a binocular field results from the overlap of the two monocular fields.

Assessment is typically done with perimetry, where stimuli are presented across a grid and the observer indicates awareness. Common methods include automated perimetry (e.g., Humphrey tests) and manual perimetry under clinic supervision. Screening tests, such as confrontation tests, provide quick checks of gross defects. The testing results are plotted as a map of sensitivity across the retina.

Normal synfält varies with age and individual anatomy; the central area around fixation is high-acuity and tied to the macula and fovea, while the far periphery contributes to motion detection and orientation. Clinically, patterns of field loss are described as tunnel vision, crescents, altitudinal deficit, or concentric loss, and help localize ocular or neurologic pathology.

Conditions affecting the visual field include glaucoma (peripheral field loss from the edges inward), retinal diseases (scotomas), optic nerve disorders, brain lesions, and cortical processing abnormalities. Traumatic or temporal lesions may cause characteristic deficits in certain quadrants or hemifields.

In Swedish usage, synfält is a standard term in ophthalmology and neurology and is critical for assessing daily functioning, such as mobility and reading, beyond visual acuity alone.