Every person has a field of vision that they can see. This field is usually 90 degree temporally, 60 degrees nasally, 50 degree superiorly, and 70 degrees inferiorly. When there are visual field defects, this often means that the person cannot see in one degree or another. However, a small vision defect is not equal to blindness. For example, they may only be able to see 45 degrees.
What Is Visual Field Defects?
Visual field defects refer to a blind area or spot appearing in the normal field of the eyes. In most cases, field defectsare consistent; however, there are times when this blind spot can be temporary or even occur from time to time. This is the case that many people experience when they have a migraine headache. Without the assistance of a field vision test,those who have a visual field defect often cannot realize the problem. These types of defects are often seen in those who have eye issues such as glaucoma and neuro-ophthalmic disorders.
What Causes Visual Field Defects?
There are several reasons why visual field defects can occur, ranging from eye diseases such as glaucoma to vascular disease, retinal disease, optic neuritis, and hereditary disorders. In addition, those who have tumors may see this defect occur. Nutritional deficiencies, exposure to certain toxins and the drugs, prescription or non-prescription, could all be the cause of visual field defects.
Other times visual field defects are caused by damage to the retina due to light, which affects the optic nerve, and this in turn affects all areas of the vision since it affects the image that is being carried to the brain. This is usually the reason that certain professionals have defects, as the work they do may put them at an increased risk.
There are those who suffer from a temporary visual field defect, which is often the result of a migraine or other related illness that is affecting the fluid levels in the eyes, and also making the eyes more sensitive. These temporary visual field defects often last less than 24 hours, but they can still cause panic for those who have this and are not fully aware of what is going on.
What to Do If I Have Visual Field Defects?
Anyone who notices that their vision is changing should be certain that they need to see a doctor as immediately as they can. The doctor can then perform tests in order to determine if the vision change is due to visual field defects. One of the tests that the doctor will perform is a vision field test. This test is virtually pain free, and simply tests what a person can see and what areas may be considered to be blind spots or areas in which they are losing vision.
The result of this test is viewed with a computer printout that shows what light thresholds the person saw, and with what part of their vision that saw them. This helps doctors to narrow down just where these blind spots may be, or where there may be the beginning stages of vision loss. With these printouts, the lighter the area is on the chart, the more that the person can see. Thus, the darker the area, the less the person is seeing in that area of sight. Many of those who have this defect are not aware of this until this test is performed, because people adjust to not having sight in the area that they have the defect, and simply go about their lives in a normal way.
Are There Any Treatments Available for Visual Field Defects?
Whether or not visual field defects can be treated by a doctor really depends on the reason why the person developed the defect. For example, those who have a defect due to a high amount of pressure in their eye, or a low amount of pressure, can be given oral medications in order to help balance this eye pressure. However, even with treatment, this is not going to cure the visual field defects that the person has. The treatment is only meant to keep the defect from becoming worse, and to avoid more vision loss in the person.
With any visual field defects, the person often becomes used to this over time, and they do not miss the vision that is deficient. However, it may mean that the person cannot perform certain activities or work in certain professions. For example, someone who has lost peripheral vision should not be driving, as this can be dangerous, or they have what is called tunnel vision.
Those who do have visual field defects often can make up for the vision loss by adjusting the way in which they look at things. For example, the person may move their eyes more in order to get the biggest vision of what they are looking at, or they may move their hand more to take in their surroundings. People with this problem may also use tricks to help them to avoid the strain that these defects may put to their eyes, such as using a highlighter to help follow along while reading, so as not to lose the place they are on the page.