What is the correct order of structures encountered by a ray of light entering the eye?

The correct order of structures encountered by a ray of light entering the eye begins with the conjunctiva, which is a thin membrane covering the front of the eye and inner eyelids. However, it is important to note that while the conjunctiva does provide some protection and lubrication, it is not directly involved in the refraction or processing of light.

Following the conjunctiva, the light passes through the cornea, which is the transparent front part of the eye that provides most of the eye's optical power due to its curvature. The cornea is crucial for the initial bending of light before it enters the eye.

Next, the light travels through the aqueous humor, which is the clear fluid in the anterior chamber of the eye located between the cornea and the lens. The aqueous humor helps maintain intraocular pressure and provides nutrients to the avascular structures like the lens.

After the aqueous humor, the light reaches the lens, which further refracts the light to focus it onto the retina at the back of the eye. The lens is flexible and can change shape to adjust focus for objects at varying distances.

Finally, the light reaches the retina, which is the inner layer of the eye containing photoreceptor cells that convert light into neural signals for the brain