Defective colour vision

R. Fletcher and J. Yoke, defective Colour Vision, Hilger, Bristol, UK, 1985. 

Comeal deposits of chloroquine may be asymptomatic or may cause halos around lights or photophobia. These are not a threat to vision and reverse when the dmg is stopped. Retinal toxicity is more serious, however, and may be irreversible. In the early stage it takes the form of visual field defects late retinopathy classically gives the picture of macular pigmentation surrounded by a ring of pigment (the bull s-eye macula). The functional defect can take the form of scotomas, photophobia, defective colour vision and decreased visual acuity resulting, in the extreme case, in blindness. 

Those with defective colour vision have been classified in the following manner (McLaran, 7-5.D.C-, 1966,82, 382 and Jordinson, 7.5.D.C., 1967, 83, 406). 

ELETCHER ROBERT, YOKE JANET (1985). Defective colour vision. Bristol Hilger. 

Fletcher R and Yoke J (1985) Defective Colour Vision. Bristol Adam Hilger. 

Wright, W.D. 1947. Researches on Normal and Defective Colour Vision. Mosby, St. Louis, MO. 

Dick F, Semple S, Chen R, et al Neurological deficits in solvent-exposed painters a syndrome including impaired colour vision, cognitive defects, tremor and loss of vibration sensation. QJM 93 655-661, 2000 Donoghue AM, Dryson EW, Wynn-Williams G Contrast sensitivity in organic-solvent-induced chronic toxic encephalopathy. J Occup Environ Med 37 1357-1363, 1995... 

Farnsworth-Munsell 100 hue test Test devised to check for both defective color vision and color discrimination ability. The test requires the subject to arrange four sets of randomized colors, contained in plastic caps, in order of hue change. The test can be administered in about fifteen minutes. It may be purchased from Munsell Color Co., Baltimore, MD. McDonald R (1997) Colour physics for industry, 2nd edn. Society of Dyers and Colourists, West Yorkshire, England. 

Verriest, G., O. Naubauer, M. Marre and A, Uvijls (1980). New investigations concerning the relationships between congenital colour vision defects and road traffic security. Inter. Ophthalmol, 2, 887-889. 

The defect of colour vision was tested by the Nagel anomaloscope in several affected members of the family, and yielded values characteristic of deutan colour blindness. It was found possible to classify members of this family as having colour blindness or normal vision with the use of Ishihara plates and these were used in the field work. HGPRTase activity was measured in erythrocyte lysates by the standard technique of incubation of labelled purine base with lysate and PRPP and measurement of the rate of conversion of purine base to nucleotide (U). Occasionally, when subjects lived in distant regions of Australia or in other countries, finger prick blood spotted on to filter paper was sent throu the post (5). The most informative portion of the family consisted of one large sibship of nine males and two females with... 

Leemans, V., Magein, H., and Destain, M.F. 1998. Defects segmentation on Golden Delicious apples by using colour machine vision. Comput. Electron. Agri. 20, 117-130. 

---