This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy, Subject name: Ophthalmology
Normal axial length of the eye - 
Select and explain. 
A. 18mm, B. 20 mm, C. 24mm, D. 28 mm
C: 24mm
Answer: C: 24mm 
Explanation: Ans. is 'c' i.e., 24 mm o The length of the eyeball is approximately 24 mm, So the distances from the cornea / crystalline lens to the retina and the focal length of optical rays focused by the comea/crystalline lens propagating in the vitreous humor and imaging on the retina, are also about 24 mm.Dimensiosn of an adult eyeAnteroposterior diameter (Length)24 mmHorizontal diameter23-5mmVertical diameter23 mmCircumference75 mmVolume6-5 mlWeight7 gm