Chapter 9, Problem 1E

Summary Introduction

Introduction: Eyes are the organs of the visual system. They detect the light and convert it into electro-chemical impulses present in the neurons. They provide vision and the ability to receive and process visual detail to the organism. Eyes help to enable many photo-response functions which are independent of vision.

Answer to Problem 1E

Correct answer: Light entering the eye first passes through the cornea, a protective window.

Explanation of Solution

The eye wall consists of three layers: sclera, choroid, and retina. Sclera is the outermost layer, choroid is the deeply pigmented middle layer, and retina is the innermost layer of the eye. Cornea is the part of the sclera in the central anterior region which allows the entry of light into the eyes. It is a transparent, protective window (front window) that controls the entry of light into the eye. It covers the iris, pupil, anterior chamber, and lens. It acts as a barrier against dirt, germs, and other factors that cause damage. The light refracts or bends when it strikes the cornea due to its curvature. The main function of cornea is refraction of light. The cornea has five layers that include corneal epithelium, bowman’s layer, corneal stroma, Descemet’s membrane, and corneal endothelium.