Colour and learning disability

The history of the use of colour in therapy for learning disability is reviewed. Relevant recent research is discussed and it is concluded that there is no convincing evidence for a retinal defect as postulated by Irlen.^A Research to separate mood and motivational effects from visual effects is recommended.     

Colour perception in pseudophakia.

Minor differences in colour perception between pseudophakic, phakic, and spectacle aphakic eyes were identified by the Pickford-Nicholson anomaloscope and the Farnsworth-Munsell 100-hue test. The results suggest that pseudophakic eyes are more sensitive to red and less sensitive to blue than aphakic eyes corrected with spectacles. Spectrophotometer measurements reveal that the Rayner-Pearce posterior chamber intraocular lens used in this study transmits an evenly balanced colour spectrum, whereas an aphakic spectacle lens exhibits significant colour distortion, reducing the red and enhancing the blue transmission. This distortion may possibly be attributed to the increased chromatic aberration in the spectacle lens compared with the intraocular lens.     

Colour contours and stereopsis.

In this study the role of colour contours in stereopsis has been investigated for random dot stereograms and for figural stereo stimuli. The main conclusion is that for random dot stereograms there are ratios of luminances for dots and background where stereopsis disappears, which could point to the possibility that colour differences alone are not sufficient to evoke stereopsis. The ratio of the luminances, however, is not unity, in general, when dots and background are of different colours. This points to colour specific effects.For figural stereograms, stereopsis does not disappear at the aforementioned ratios of the luminances of figure and background. Here colour certainly has a contribution to stereopsis on its own.In another series of experiments the influence of colour rivalry on the stereo thresholds has been investigated.     

Colour discrimination ellipses in choroideremia

Graefe's Archive for Clinical and Experimental Ophthalmology - The purpose of this study was to characterise alterations in colour discrimination in a cohort of patients with choroideremia...