GROSS ANATOMY

Detailed explanation-1: -Emmetropia, myopia and hyperopia Briefly, a normal-sized eye, anteroposterior dimension 22–24 mm, is termed an emmetropic eye and is one in which the image is focused sharply on the retina by the combined refracting properties of the cornea and the lens (eFig.

Detailed explanation-2: -The mean adult values for axial length are 22-25 mm and mean refractive power-25.0-+1.0 D. The mean depth of the anterior chamber in an adult emmetropic eye is 3-4 mm. Accumulating evidence from human studies point out that both heredity and the environment contribute to the refractive power of the eye.

Detailed explanation-3: -Conclusion. The size of a human adult eye is approximately 24.2 mm (transverse) × 23.7 mm (sagittal) × 22.0–24.8 mm (axial) with no significant difference between sexes and age groups. In the transverse diameter, the eyeball size may vary from 21 mm to 27 mm.

Detailed explanation-4: -Like many ophthalmology instruments, they have spherical and cylindrical measurement ranges of-30 to +25D/±10D respectively.