Isochromatic chas are used for: March 2008: (A) Contrast sensitivity, (B) Testing colour vision, (C) Visual fields chaing, (D) Visual acuity testing
Answer is B. Ans. B: Testing colour vision Isochromatic chas/Japanese Ishihara chas is used for testing colour vision and it largely identifies red-green anomalies. The American Hardy-Rand-Ritler (H-R-R) test identifies blue-yellow anomalies.