During Worth 4 Dot testing, if four dots are seen, what does this indicate?

• A. OD suppression
• B. OS suppression
• C. Flat fusion without suppression
• D. Diplopia

Answer: (C)

Worth 4 Dot tests use red-green goggles to see how well the eyes work together. The setup presents four lights: red, green, and two white dots. The colored dots are seen only by the eye with the matching filter, while the white dots are seen by both eyes. When both eyes are open and properly aligned with no suppression, you see all four dots, meaning flat fusion. So seeing four dots indicates that both eyes are contributing to a single, fused percept with no suppression and no diplopia. If one eye were suppressed, you’d see fewer than four dots (usually three), and if there were diplopia from misalignment, you’d perceive two separate images rather than a single set of four.