title: New paediatric contrast test: Hiding Heidi low-contrast 'face' test.
abstract: BACKGROUND
  The Hiding Heidi low-contrast 'face' test is a new paediatric contrast test to evaluate the ability to detect objects with low contrast. The purpose of the present study was to compare the Hiding Heidi low-contrast 'face' test (HH) with the Pelli-Robson contrast sensitivity test (PR) and the functional acuity contrast test (FACT) in the low-contrast assessment.
  
  
  METHODS
  Thirty university students participated in the present study. The contrast ability was evaluated by using three different methods: HH, PR and FACT. The HH was repeated on two separate occasions to test the repeatability.
  
  
  RESULTS
  There was a significant positive correlation between HH and PR (r = 0.65, P < 0.01); between HH and FACT at 6 cycles per degree (c.p.d.; r = 0.64, P < 0.01); between HH and FACT at 3 c.p.d. (r = 0.91, P < 0.01); and between HH and FACT at 1.5 c.p.d. (r = 0.56, P < 0.01). The paired t-test showed a significant difference between HH and PR (t = -6.05, P < 0.01); between HH and FACT at 6 c.p.d. (t = -11.16, P < 0.01); between HH and FACT at 3 c.p.d. (t = -8.35, P < 0.01); and between HH and FACT at 1.5 c.p.d. (t = -5.64, P < 0.01). They had good agreement. The HH had a high repeatability.
  
  
  CONCLUSIONS
  The HH had a positive correlation but produced significantly different readings when compared with FACT and PR. The features and role of HH in clinical contrast sensitivity assessment are discussed.
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity; D005145:Face; D006801:Humans; D010372:Pediatrics / Q000379:methods*; D015203:Reproducibility of Results; D014787:Vision Tests / Q000379:methods* / Q000592:standards; D014792:Visual Acuity