It is often assumed that persons who develop ocular disease have some form of visual experience that makes them aware of their deficits. However, in the case of peripheral field loss or decreasing vision in dim lighting, as in retinitis pigmentosa, for example, symptoms are more obscure and may not be as easily identified by the persons who have…

Visual attention has temporal limitations. In the attentional blink (AB) a stream of stimuli such as letters or digits are presented to a participant on a computer monitor at a rapid rate. Embedded in the stream are two targets that the participant must try to identify. Identification of the second target is severely impaired if it is presented…

Damage to the areas of the brain that are responsible for higher visual processing can lead to severe cerebral visual impairment (CVI). The prognosis for higher cognitive visual functions in children with CVI is not well described. We therefore present our six-year follow-up of a boy with CVI and highlight intervention approaches that have proved…

Age-related macular degeneration (AMD) is a leading cause of vision loss in Americans aged 60 and older. The loss of central vision from AMD can decrease visual acuity, contrast sensitivity, glare sensitivity, color discrimination, and the ability to adapt to changes in lighting conditions. Older adults with vision loss often have other chronic,…

Vision is the dominant sense, and the eyes are connected with almost every other part of the brain. If the vision system is poorly developed, children trying to learn suffer. Without good up close vision, students are handicapped even if no one knows or suspects it--they may not even know it themselves. Students do not know that the way they see…

It is generally appreciated that patients with macular disease frequently experience reduced visual acuity. It is not as widely appreciated that they often have significant central visual field disruption, which, by itself, can cause significant problems with activities of daily living, such as reading and driving, even when they maintain good…

Retinitis pigmentosa is a rod-cone dystrophy, commonly genetic in nature. Approximately 60-80% of those with retinitis pigmentosa inherit it by an autosomal recessive transmission (Brilliant, 1999). There have been some reported cases with no known family history. The symptoms of retinitis pigmentosa are decreased acuity, photophobia, night…

Techniques used by the Special Visual Assessment Clinic for the Handicapped at the University of California-Berkeley School of Optometry are designed to serve handicapped children and adults generally considered "difficult to assess." This article describes the clinic's assessment goals, clientele, and methods for assessing visual ability and…

Describes Intermittent Central Suppression (ICS), a treatable eye malfunction that can make reading difficult. Reports that some students with ICS are not diagnosed through standard vision acuity tests and are misdiagnosed as learning disabled. Presents a study that found that students who were treated for ICS stayed in school longer than students…

Physical changes in and conditions of the eye associated with the normal aging process are discussed with reference to their impact on performance in physical and recreational activities. Descriptions are given of characteristic changes in visual acuity in the areas of: (1) presbyopia (inability to clearly focus near images); (2) sensitivity to…

In order to assess vision in Alzheimer's disease, gerontologists must use tests that make minimal cognitive demands on the subject. Using such tests revealed a pattern of deficits in color discrimination, stereoacuity, contrast sensitivity, and backward masking. Impaired vision predicts deficient performance on numerous tests of cognition. (JPS)

Although several vision screening techniques are available for infants, none is routinely used. Visual deficits are often first detected through required preschool vision screenings, which vary in their comprehensiveness. No standardization for testing or administration exists. Some of the testing procedures used may have inappropriately high…

The visual acuity of 8 children, aged 2-7, with low vision and multiple handicaps was effectively tested using the Teller Acuity Cards and a preferential-looking procedure with operant modification. This inexpensive procedure was found to be suitable for at-home testing by itinerant vision specialists in developing countries or rural areas. (DB)

Vision assessment in multiply impaired children (ages 3-19, n=50) was studied by evaluating questionnaires completed by the psychological services responsible for determining their educational requirements. Relatively few conducted assessments of visual functioning but chose instead to determine level of visual impairment from medical,…

Describes a corrective method of color adaptation designed to allow most, if not all, individuals to participate in the learning process as well as social and work-related environments. Provides a concise summation of facts and theories concerning color deficiency. Includes anatomical drawings, graphs, and statistical data. (MJP)