Visual Fields
A Snellen letter chart test measures how you see straight ahead whereas a Visual Field test measures how you see centrally as well as peripherally.
Visual Field Analysis
We can get a measure of how wide an area you can register by asking you to focus on a central object and flashing small lights in your peripheral field. There are many ocular and health conditions that can change your Visual Field - among them; glaucoma, diabetic retinopathy, stroke, pituitary disease and brain tumours.
Periodic field exams are charted in glaucoma patients to track the progression of disease.
Normal visual field
(the dark area is the eye’s natural blindspot)
Visual field of patient with glaucoma
(the dark area shows loss in the superior field)
Visual field of patient with tumour
(the dark areas show a bilateral loss in the temporal field)