title: The UWCDot colour vision test and low vision.
abstract: OBJECTIVE
  Previous studies have shown that colour vision defects are common in the low vision population even when properly designed tests are used. However, there are very few clinical tests available that are suitable for this group of patients. One of the more common is the Jumbo D-15 (JD15). Although this test uses caps more suitable for the reduced acuity, it requires the patient to have some knowledge of colour order and sufficient dexterity to manipulate the caps. We compared the JD15 with the University of Waterloo Colored Dot test (UWCDot), which has neither of these requirements, to determine whether the UWCDot test could be used as a substitute for the JD15.
  
  
  METHODS
  The colour vision of 40 consecutive low vision patients was evaluated with both tests. Acuities ranged from 6/6 to 6/1600 with a median value of 6/30.
  
  
  RESULTS
  All subjects could perform both tests. The kappa coefficient of agreement between tests was high at 0.85 when any major crossing was a failure on the JD15 and any mistake was a failure on the UWCDot. Classification of the type of defect was also reasonable when the defect was relatively severe.
  
  
  CONCLUSIONS
  The UWCDot can be used as a substitute for the JD15 in the low vision clinic. Both tests identify individuals with moderate-to-severe deficiencies, but the UWCDot does not require any manual dexterity and it does not require knowledge of colour-order.
authors.affiliation: School of Optometry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada. jhovis@uwaterloo.ca
authors.forename: Jeffery K
authors.initials: JK
authors.lastname: Hovis
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Leat
authors.forename: Karen
authors.initials: K
authors.lastname: Epp
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003119:Color Perception Tests; D003117:Color Vision Defects / Q000175:diagnosis*; D006801:Humans; D008875:Middle Aged; D015354:Vision, Low / Q000503:physiopathology*