Pen Torch

Pen Torch — Uses + Viva

Main use:
A pen torch is used to assess the pupillary light reflex and to provide illumination during examination.

Common uses

• Assess direct and consensual pupillary light reflexes

• Check pupil size, shape, and symmetry

• Examine the oral cavity and throat

• Inspect the eyes and external ear

• Provide illumination during general examination

Important Viva Questions

Q. What is a pen torch?
A. A small, portable light source used for clinical examination.

Q. What is its most important use?
A. To assess the pupillary light reflex.

Q. What are the two components of the pupillary light reflex?
A. Direct and consensual light reflexes.

Q. What is a direct light reflex?
A. Constriction of the pupil of the eye into which light is shone.

Q. What is a consensual light reflex?
A. Constriction of the opposite pupil when light is shone into one eye.

Q. Why is the light usually introduced from the side?
A. To minimize accommodation and convergence.

Q. What cranial nerve is the afferent limb?
A. Optic nerve (CN II).

Q. What cranial nerve is the efferent limb?
A. Oculomotor nerve (CN III).

One-line exam answer:
👉 “Pen torch is mainly used to examine the pupils and assess the direct and consensual pupillary light reflexes.”