This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Lateral rectus palsy is characterized by - 
Select and explain. 
A. Crossed diplopia, B. Uncrossed diplopia, C. Suppression of eye ball, D. Upward rotated eye ball
B: Uncrossed diplopia
Answer: B: Uncrossed diplopia 
Explanation: First see the difference between phoria and tropia. Suffix phoria is used in latent squint, e.g. esophoria and exophoria. Suffix tropia is used in manifest squints (concomitant and paralytic) e.g. esotropia or exotropia.
Diplopia is a feature of paralytic esotropia or exotropia but not concomitant esotropia / exotropia or esophoria / exophoria (latent squint).


Uncrossed diplopia: - convergent squint (Esotropia) as in lateral rectus palsy.
Crossed diplopia: - Divergent squint (exotropia) as in medial rectus palsy.