What are the primary refractive media of the eye?

The primary refractive media of the eye are crucial components that help focus light onto the retina, enabling clear vision. The correct response identifies the cornea, aqueous humor, crystalline lens, and vitreous humor as these media.

The cornea is the eye's outermost layer and has a high refractive power due to its curvature and transparency. It plays a significant role in bending (refracting) incoming light. Following the cornea, the aqueous humor—a clear fluid found in the anterior chamber of the eye—also assists in light refraction, although its role is less pronounced.

The crystalline lens is located behind the pupil and adjusts its shape to fine-tune the focus of light as it enters the eye, allowing for sharp vision at various distances. Finally, the vitreous humor, a gel-like substance filling the larger posterior chamber of the eye, helps maintain the eye’s shape and supports the retina while providing minimal additional refractive power.

In contrast, the other options include elements that do not primarily serve as refractive media. The sclera is more of a protective outer layer, the iris regulates light entry but does not refract light, the conjunctiva is a mucous membrane, and the retina is the sensory layer that detects