Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What type of condition is indicated by a focal loss within a visual field?

1. Scotoma

2. Diplopia

3. Photophobia

4. Astigmatism

The correct answer is: Scotoma

A focal loss within a visual field specifically refers to a scotoma, which is an area of partial or complete loss of vision in an otherwise normal visual field. Scotomas can be caused by various ocular or neurological conditions and may present as a dark or blank spot within the visual field. They can vary in size, shape, and location, but the defining characteristic is that they are confined to a specific area rather than affecting the entire visual field. On the other hand, the other conditions listed do not describe a focal vision loss. Diplopia refers to double vision, where a person sees two images of one object, indicating an issue with binocular vision. Photophobia is an abnormal sensitivity to light, which affects how light is perceived rather than indicating a loss in a specific visual field area. Astigmatism is a refractive error caused by an irregular shape of the cornea or lens, leading to blurred vision rather than focal loss in the visual field.