Question

(a) redraw your diagram of the eye correctly focusing a distant object onto the retina, assuming the eye is air-filled. show how this changes if the eye is actually filled with water. is the image now in front or behind the retina?

Answer 1

In an air-filled eye, the diagram would depict light converging onto the retina for correct focus on a distant object. If the eye is filled with water, the image would now form behind the retina.

Step-by-step explanation:

In an air-filled eye, light rays entering the eye converge and focus directly onto the retina, ensuring clear vision of distant objects. However, when the eye is filled with water, the refractive index of water is higher than that of air.

This causes light to refract more, leading to a change in the focal point. As a result, the image now forms behind the retina, causing a shift in the focal point. This displacement can result in blurred vision as the image doesn't precisely converge onto the retina.

Answer 2

In an air-filled eye, light rays converge correctly on the retina, but when filled with water, the index of refraction changes, causing the focal point to move in front of the retina, which results in the distortion of vision for distant objects.

Step-by-step explanation:

The process of focusing distant objects onto the retina in a human eye filled with air involves the convergence of light rays primarily at the cornea and then upon entering and exiting the lens.

This produces a real, inverted image on the retina. When the eye is filled with water instead of air, the index of refraction changes due to water's higher refractive index compared to air. This change affects the focal length of the lens based on the lens maker's equation.

As a result, the focal point will shift, and the image will no longer be correctly focused on the retina; instead, it typically forms in front of the retina, similar to the conditions in myopia or nearsightedness, where distant objects appear blurred.

In an air-filled eye, a relaxed, normal-vision eye will focus parallel rays of light onto the retina. For an eye completely filled with water, this would no longer occur, and the individual would experience vision distortion, where distant objects might appear blurred or out of focus.