Which of the following is NOT listed as a contrast sensitivity chart used in assessment?

• A. Mars chart
• B. Bailey-Lovie chart
• C. Hiding Heidi chart
• D. Snellen chart

Answer: (D)

Contrast sensitivity tests measure how well a person can detect or recognize objects as their contrast with the background decreases, which reveals functional vision in everyday situations. The Mars chart and the Hiding Heidi chart are designed specifically to assess this ability by presenting targets at reduced contrasts. The Bailey-Lovie chart, while often used as a high-contrast acuity chart with standardized letter sizing, is typically associated with acuity assessment rather than contrast thresholds. The Snellen chart, on the other hand, uses high-contrast letters to measure visual acuity and does not test performance across varying contrasts. Therefore, the Snellen chart is not a contrast sensitivity chart.