During examination of optic neuritis, which finding is commonly observed?

• A. Pain with eye movements
• B. No pain on movement
• C. Normal pupillary reactions
• D. Color vision is normal

Answer: (A)

Pain with eye movements is commonly observed because inflammation of the optic nerve makes it highly sensitive to the mechanical stress of moving the eye. This leads to aching or sharp pain that worsens with movements, especially in the acute phase of optic neuritis. Visual loss is usually rapid and unilateral, and there is often a relative afferent pupillary defect due to reduced input from the affected nerve. Color vision is frequently impaired (red desaturation), so normal color vision is not typical. Normal pupillary reactions are less likely because the afferent defect alters the pupil response. So, the finding most commonly observed is pain with eye movements.