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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Longest pa of the optic nerve is
assistant
The correct answer is  The optic nerve is about 47- 50 mm in length and can be divided into 4 pas : intraocular (1mm), intraorbital (30mm), intracanalicular (6-9mm) and intracranial (10mm). Refer comprehensive ophthalmology 6th edition , A K Khurana , page no. 310.