ABO Ophthalmology Complete Practice Exam 2025

The primary function of the vitreous humor is to maintain the shape of the eye. The vitreous humor is a clear gel-like substance that fills the space between the lens and the retina, comprising about 80% of the eye's total volume. Its structural integrity is crucial for supporting the eyeball's spherical shape, which is essential for proper optical function.

By keeping the shape of the eye intact, the vitreous humor allows for an optimal alignment of the optical components, ensuring that light is focused accurately onto the retina. This helps in maintaining visual clarity and contributes to overall eye health. The viscosity of the vitreous also plays a role in stabilizing the retina, ensuring that it remains in place against the choroid layer.

In contrast, the other functions listed, such as regulating light entry, aiding in color perception, and facilitating fluid drainage, are primarily associated with other eye components, such as the cornea, lens, and aqueous humor. Thus, the vitreous humor's main role is distinctly centered on structural support rather than these other functions.