What Is Low Vision?
Low vision is an umbrella term used to describe eyesight from a moderate vision-impairment to near-total blindness after correction from surgery, medication, contact lenses, or glasses. One with low vision is lacking one or more of the following: clear vision, central vision, peripheral vision, depth perception, contrast sensitivity, or the ability to process what their eyes are seeing.
While low vision is commonly classified as 20/70 or poorer in the better eye with correction or a significant visual field loss, low vision is defined, for the purpose of educational services, as vision loss that interferes with the ability to perform daily or educational activities. The latter definition is preferred as it includes 1) those with visual processing disorders, referred to as brain-based visual impairments or cerebral visual impairments (CVI), and 2) those whose vision may appear adequate in a clinical setting yet is impaired in a functional setting such as a dimly lit room, a visually cluttered space, where depth perception is required, or a low-contrast environment.
How Is Low Vision Diagnosed?
Low vision is caused from an eye disease or eye condition which is diagnosed by an ophthalmologist.
Are There Treatments for Low Vision?
Treatment for low vision will depend on the treatments available for your child's specific eye condition.
How Would You Describe the Eyesight of One with Low Vision and How Will My Child Function with Low Vision?
There is much variation in the quantity and quality of remaining useful vision for individuals with low vision. Several professionals can assess your child’s vision across a variety of environments and situations in effort to understand how your child sees and to help your child better function with low vision.
A low vision specialist or certified low vision therapist, an optometrist or ophthalmologist who is trained in low vision, can administer vision testing to determine how your child can maximize any useful vision. Your child may be prescribed low vision devices, including optical devices such as a monocular for distance viewing or hand-held magnifier for near viewing and non-optical devices such as dark-lined paper or a reading stand.
Your child's teacher of students with visual impairments should perform a functional vision assessment to learn how your child uses any remaining vision and a learning media assessment to determine which senses your child primarily uses to get information from the environment. These assessments, along with an orientation and mobility assessment conducted by a mobility specialist, will give the educational team information needed to make specific recommendations for your child to best access learning material and his or her environment.
You may learn your child has difficulty recognizing faces and facial expressions, accessing information from a distance, identifying small images or letters on paper, or travelling safely. If this is the case, your child may benefit from travel training from the mobility specialist, increased contrast of the environment, increased contrast of print by using a CCTV or screen-magnification software, and increased room and task lighting. Your child may also benefit from assistive technology to more easily write, read, use the computer, and access information; and techniques and additional accommodations to perform activities with limited vision.
Your child may also be taught to complete tasks without use of vision. Your child may be taught braille, use of screen-reading software to use the computer, and other techniques for performing life skills and academic tasks from the teacher of students with visual impairments.
All the above information and articles are introduced from http://www.afb.org/info/specific-eye-conditions/low-vision/45