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…

The impact of repeated and prolonged attempts at remembering on false memory rates was assessed in three experiments. Participants saw and imagined pictures and then made repeated recall attempts before taking a source memory test. Although the number of items recalled increased with repeated tests, the net gains were associated with more source…

The authors present 10 experiments that challenge some central assumptions of the dominant theories of visual search. Their results reveal that the complexity (or redundancy) of nontarget items is a crucial but overlooked determinant of search efficiency. The authors offer a new theoretical outline that emphasizes the importance of nontarget…

The eye movements of skilled readers are typically very regular (K. Rayner, 1998). This regularity may arise as a result of the perceptual, cognitive, and motor limitations of the reader (e.g., limited visual acuity) and the inherent constraints of the task (e.g., identifying the words in their correct order). To examine this hypothesis,…

For more than 150 years, printers have been faithfully reproducing continuous tone originals using halftoning techniques. For about 120 years, printers could only use the AM halftoning technique invented by Henry Talbot. In recent years, the advent of powerful raster image processors and high-resolution output devices has increased the variety of…

Background: The prevalence of visual impairments in people with severe and profound multiple disabilities (SPMD) is the subject of considerable debate and is difficult to assess. Methods: In a typical Dutch care organization, all clients with SPMD (n = 76) participated in the study and specific instruments adapted to these clients (requiring a…

A study of children enrolled in a year-round preschool program for the "culturally disadvantaged" in Tampa, Florida revealed that children with defective vision performed more poorly on both the Peabody Picture Vocabulary Test and Metropolitan Readiness Test. (Author/JM)

Based on dissertation for EdD degree at University of California, Berkeley (1968).

A new test designed to detect an hereditary eye disease called retinitis pigmentosa (RP) is described. This condition is revealed by pigmentation in the retina, but early diagnosis is difficult because the symptoms are subtle, and since it is genetically recessive it frequently occurs in families with no history of early blindness. In many cases…

This paper reports the major findings and interprets the results of longitudinal and cross-sectional exPeriments concerning the development of visual accommodation in infants 1 to 3 months of age. The stimulus was a high-contrast, random checkerboard which was presented at three different distances from the infants (25, 50 or 100 cm). The physical…

Tests of preschool children have revealed that children from low income groups have more visual problems than children from higher income families; it is suggested that comprehensive vision screening be provided children upon reaching school age so that problems can be corrected early. (JD)

The study assessed transfer of visual training for myopia using two different training stimuli and a single subject A-B-C-A design with a male student volunteer. A procedure including stimulus fading and reinforcement (positive verbal feedback) was used to effectively improve performance on both behavioral acuity tests during the training phases…

A study involving two college students with visual impairments which made them incapable of accommodating visually revealed that Ss improved recognition efficiency with feedback but did not generalize the efficiency from trained to untrained stimuli of similar complexity. (CL)