What is Visual Field
The visual field is the area of space that an individual can see at the same time without moving their eyes or head. It is essentially the field of vision or the extent of peripheral vision. The visual field can be measured in degrees from the center, and it is an important aspect of assessing visual function.
A normal visual field includes a range of approximately 95 degrees towards the ear (temporally) and 60 degrees towards the nose (nasally) from the center. It also includes a vertical field range of 60 degrees above and 75 degrees below the center. The optic nerve, which is responsible for transmitting visual information to the brain, does not have photoreceptor cells. This creates a blind spot in the visual field, which is approximately 15 degrees towards the ear (temporally) from the center.
Visual field is also used in the field of clinical perimetry and visual perimetry to assess the extent and quality of a person’s vision. Visual field testing involves measuring and mapping the visual field to detect any abnormalities or changes in the field of vision. It is a crucial tool in diagnosing and monitoring various eye conditions and diseases, such as glaucoma and retinitis pigmentosa.
Frequently Asked Questions
What Is the Normal Visual Field Range
A typical visual field for each eye typically covers a horizontal range of approximately 120 degrees and a vertical range of about 90 degrees.
How Do You Measure Visual Field
You will be instructed to focus on an object directly in front of you, such as the doctor’s nose, while one of your eyes is covered. During the examination, your doctor may present various numbers of fingers within your peripheral vision and ask you to indicate how many you can see while maintaining your gaze on the target in front of you.
How Do I Know What My Visual Field Is
To determine your visual field, your doctor may conduct a test where you wear a blindfold and they hold up various fingers in your peripheral vision, asking you to report what you see. Another method is the automated static perimetry test, which provides a more comprehensive analysis of your field of vision, allowing your doctor to create a complete image.
What Is Visual Field Loss
Visual field loss refers to the loss of a specific area of vision within one’s visual field. This type of loss typically occurs after a stroke or brain injury and tends to affect both eyes. It is common for the lost portion of vision to correspond with any weakness experienced on the same side of the face, arms, or legs.