26 year old female patient presents to OPD with inability to focus on close objects, but can clearly see the distant objects . Most likely damage to which structure will lead to following condition ?
High-Yield Explanation
Damage to parasympathetic ciliary ganglion and parasympathetic fibres in sho ciliary nerve impairs the ability to focus on close objects (accommodation). Because the patient can move his eyeballs normally, the oculomotor nerve is not damaged even if this nerve contains preganglionic parasympathetic fibres. Patient can see distant objects clearly because the long ciliary nerve also carries sympathetic fibres to the dilator pupillae. Ability to move eyeball normally indicates that the oculomotor, trochlear, and abducens nerves are intact.