Vision impairment can occur at any age. In adults, macular degeneration is the primary cause of blindness in the United States. However, congenital conditions, injury, cataracts, glaucoma, optic nerve degeneration, and a variety of other problems can cause loss of vision. Most vision impairments result in what has been termed low vision rather than total blindness. Serious vision impairment may render the person dependent upon others to read, write, walk safely, and read price tags and medicine bottle labels. A person with low vision may not be able to see and recognize faces of friends or family across the room. Such problems can cause frustration, anxiety, and depression.
Given the increasing incidence and prevalence of persons with severe but partial vision impairment, it is important to understand low vision services. When medical or surgical treatment cannot provide any further improvement, or when medical or surgical treatment must be delayed, a low vision evaluation is recommended.
Low vision services are multidisciplinary and utilize special vision examination techniques and optical aids to improve the individual’s vision, and thereby rehabilitate functional abilities and skills. The primary objective of low vision services is to increase independence.
The low vision examination is a specialized form of vision analysis which the doctor begins by analyzing functional abilities the moment the person walks into the office. Functional assessment is important because it allows the low vision specialist to better evaluate the individual’s abilities and needs, the extent to which the sight loss may be interfering with vision functioning, the areas with which testing should begin, and, in general, the type(s) of optical aids that may help the person meet his or her needs. This continued behavioral analysis, in conjunction with assessment of function, adds meaning to the measurements of sight that will be made during the examination. An in-depth history is taken, and social workers, educators, and other professionals may need to be consulted to further assess needs and abilities.
The low vision examination differs from routine eye examinations in that special methods of testing must be used to determine refractive status, acuities (near and far), visual field, and eye health in order to analyze areas of best residual vision so that the specific types of optical aids providing the most assistance can be recommended. Procedures are often adapted to elicit the vision that the patient retains. On the basis of this analysis and the above described behavioral observations and functional analysis, special lens and optical aids of various types are prescribed to improve acuity levels.
Types of Vision Problems Frequently Seen
- Macular Degeneration
- Retinitis Pigmentosa
- Other conditions of vision impairment
There are literally thousands of types and powers of optical aids from simple magnifiers to more sophisticated spectacle mounted telescopes for seeing at distance, microscopes mounted in glasses for reading, and electronic equipment such as closed circuit televisions that can magnify print up to 100 times, often enabling a person with low vision to read again. Frequently, blind spots or visual field losses will interfere with balance and posture. When these vision problems occur special enhanced field prisms can be prescribed to improve the person’s visual field awareness on the affected side. Appropriate training in the use of optical aids as well as follow-up services will be recommended based on individual needs.
Optical aids and special spectacle lenses improve visual acuity, thereby directly improving sight. However, improvement of performance and function depends upon how the patient utilizes his enhanced sight. Optometric therapy programs may be recommended based on a patient’s needs, in order to optimize the ability to use the improved visual acuity. When recommended, they will be provided in our office.
Low vision services are a means to redevelop effective visual functioning. The purpose of the service is to increase independence. Please contact us at the Padula Institute of Vision if you would like to schedule a low vision evaluation.