Which sign is typically preserved in cataract patients despite lens opacities?

Which sign is typically preserved in cataract patients despite lens opacities?

• A. Dazzle reflex
• B. Pupillary constriction deficit
• C. Keratitic reaction
• D. Accommodative spasm

Answer: (A)

The dazzle reflex is a protective, brainstem–mediated response to bright light that can stay intact even when the lens is cloudy. In cataract, the opacities reduce the amount and quality of light reaching the retina, blurring vision, but the reflexive blink or eyelid closure triggered by sudden, intense illumination does not depend on forming a clear image. This means you can still observe a blink or lid closure when a bright light is shone into the eye, even though vision is compromised. This is why the dazzle sign is typically preserved in cataract patients despite lens opacities. In contrast, the pupillary constriction response relies on light transmission through the lens to the retina and can be diminished when light entry is markedly reduced. The other options—keratitic reaction and accommodative spasm—do not specifically reflect the preserved, reflexive response to bright light seen in cataracts.

The dazzle reflex is a protective, brainstem–mediated response to bright light that can stay intact even when the lens is cloudy. In cataract, the opacities reduce the amount and quality of light reaching the retina, blurring vision, but the reflexive blink or eyelid closure triggered by sudden, intense illumination does not depend on forming a clear image. This means you can still observe a blink or lid closure when a bright light is shone into the eye, even though vision is compromised.

This is why the dazzle sign is typically preserved in cataract patients despite lens opacities. In contrast, the pupillary constriction response relies on light transmission through the lens to the retina and can be diminished when light entry is markedly reduced. The other options—keratitic reaction and accommodative spasm—do not specifically reflect the preserved, reflexive response to bright light seen in cataracts.