The visual field is a space in which multiple objects can be seen simultaneously by our eye that is steadily fixed. Daily activities such as reading, driving and shopping can all require a healthy visual field. When our visual system is functioning correctly, the brain tells us quickly where an object is in space and what it is. Being aware of our physical surroundings is essential.
Visual field loss is caused by traumatic brain injuries, autism, stroke and neurological diseases. Stress or fatigue also cause a person's functional visual field to constrict.
If you experience any of these symptoms, after a thorough visual field evaluation, your eye doctor can prescribe a proper treatment and management plan to improve your visual function.
Altitudinal visual field defect refers to loss of visual field in the horizontal half.
Bitemporal visual field defect is the loss of visual field in half of both right and left visual field.
Homonymous hemianopsia is the absence of vision in the same half of each eye's visual field. It is most commonly caused by stroke. It is present in 30% of stroke patients.
Central scotoma is a black spot in your central vision. It is caused by glaucoma and other retinal diseases
A visual spatial inattention is a deficit of awareness and attention to one side of space. Even though the patient has good vision, half of their visual world no longer matters to them. In most cases, the neglected side is the left. There is a tendency for the patient to bump into things on one side and not pay attention to things on that side. Their mental images are half as well, not due to a problem with vision, but due to a problem with consciousness.
A magnocellular deficit is a disorder that impairs the ability to learn and read. It leads to difficulties such as reading comprehension and poor reading fluency. When trying to read small letters, patients complain that they move around and blur. Magnocellular deficits cause patients to be uncoordinated and clumsy, and they have trouble balancing.
Neuro vision rehabilitation addresses the peripheral system with the help of lenses, prisms and binasal occlusion. Lenses help to stabilize the vestibular ocular systems. Base in or yoked prisms may also be prescribed by our eye doctor. Binasal occlusion covers the nasal visual field to reduce the stress on your visual system. It helps with your gait and balance.
Filters may be incorporated into your eyeglasses to reduce glare and enhance contrast. Green filter combined with blue help with photosensitivity. Blue filter reduces ocular pain with eye movements. Yellow filter reduces blue light from passing through the lens and helps with computer and fluorescent lighting.
Prisms can change the spatial orientation of the patient. It can expand space or constrict space. They are used in vision therapy and/or a full time prescription in glasses. They are prescribed by an eye doctor after a thorough eye exam.
Peli prisms
They are primarily used to locate objects outside the visual field of patients with homonymous hemianopsia. They are placed on the lens of the temporal field defect. You do not actually view through the prisms but if an object is seen peripherally on the field loss side, they are used to detect the object. It is advised to practice walking and use of stairs while wearing the peli prism. They may be fit on the upper visual field first if you are having a hard time adapting to it.
Yoked Prisms
Yoked prisms can cause improvement in posture and gait when it is prescribed correctly. They also enhance the functional visual field. The key to effective treatment with prism lenses is how it's being prescribed.
In this exercise, you will be asked to scan into the side of the field loss and to remember as many objects there as possible. Then you will be asked to look straight ahead to visualize those objects. After that you will point to the area where you saw the objects. While you are still pointing, you will be asked to turn your head so that you could view the missing field.
These glasses have the widest viewing area, which enhances the visual field. If you're out shopping, these glasses can be very helpful. When crossing the street, these glasses can also be helpful because they allow you to see the cars more clearly. Depending on state law, patients with hemianopsia who wear side vision awareness glasses may be able to drive again.
Visual field loss severely impairs your vision and ability to perform daily tasks. It can be caused by traumatic brain injuries, autism, stroke and neurological diseases. With a functional visual field test, our eye doctors will be able to provide you with the most appropriate treatment and tools to improve your visual function and manage or treat your condition.