Deviation of visual axis from its normal alignment is known as?

Appeared in: IGNOU Post B. SC. Nursing entrance -2021

Explanation

Strabismus is the medical term for any misalignment of the eyes, where the visual axes do not point at the same object simultaneously.
This condition is also commonly referred to as 'squint' or 'cross-eye'.
The misalignment can be constant or intermittent and can occur in different directions: inward (esotropia), outward (exotropia), upward (hypertropia), or downward (hypotropia).

Option A: Ptosis is the drooping of the upper eyelid, a condition affecting the eyelid's position, not the alignment of the eyeball's visual axis.
Option B: A cataract is the clouding or opacification of the eye's lens, which impairs vision clarity but does not cause the eye to deviate from its axis.
Option D: Glaucoma is a condition involving optic nerve damage, typically from high intraocular pressure, leading to peripheral vision loss. It does not involve misalignment of the visual axis.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Definition of Strabismus (eye misalignment) as background academic context rather than a clinical decision trigger.
Early detection of strabismus in children is critical for nurses, as untreated misalignment can lead to amblyopia ('lazy eye'), a condition of reduced vision in one eye that can become permanent.
Nursing assessment includes the cover-uncover test and observing the corneal light reflex (Hirschberg test) to check for ocular alignment.
What if? If an adult patient presents with a new, sudden onset of strabismus, it is a significant neurological sign. The nurse should suspect a potential cranial nerve palsy (affecting nerves III, IV, or VI), stroke, or other intracranial pathology and ensure prompt neurological evaluation.

How to Approach the Question

This is a direct recall question asking for a medical definition.
Analyze the keywords in the stem: 'deviation,' 'visual axis,' and 'alignment.' These point to a problem with how the eyes are positioned or move together.
Evaluate each option against this core concept.
Ptosis (eyelid), Cataract (lens), and Glaucoma (optic nerve/pressure) relate to different parts of the eye or different pathologies. Eliminate them as they do not describe misalignment.
Strabismus directly matches the definition of misaligned visual axes. Select this as the correct answer.

Concept Tested & Keywords

Q5gcxjMfjKXAMy6BKwI8_m

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 1732-1734

E6 Ghai Essential Pediatrics(pp 26-904 of 913) p. 707-709

Practise the full IGNOU Post B. SC. Nursing entrance -2021

Attempt every question from this paper in a timed mock, then review the full solution for each one.