Physics and Eye Health

Knowing the structure of Human Eye and the Physics behind the working of eye will help us maintaining good eye health.

Let's have a look at the structure of Human Eye

Parts of Eye

Before discussing Eye Health Let's have a look at the parts of Human Eye
The eye has many parts. Some of the main parts are listed and described below.
•eye lens ◦The transparent crystalline lens of the eye is located immediately behind the iris. •cornea ◦The cornea is a transparent dome which serves as the outer window of the eye. The cornea is the most powerful structure focusing light entering the eye. •retina ◦The retina is the innermost layer of the eye. It is composed of nerve tissue which senses the light entering the eye.
◦The retina sends impulses through the optic nerve back to the brain, which translates the impulses into images that we see.
◦There are 4 types of light-sensitive receptors found in the retina
1.rods
2.cones that absorb long-wavelength light (red)
3.cones that absorb middle-wavelength light (green)
4.cones that absorb short-wavelength light (blue)
•pupil ◦The pupil is the hole in the center of the eye where light passes through. •iris
◦The iris is the colored part of the eye. It is a thin diaphragm composed mostly of connective tissue and smooth muscle fibers. The iris lies between the cornea and the crystalline lens.
•optic nerve
◦The optic nerve is a continuation of the axons of the ganglion cells in the retina. It acts acts like a cable connecting the eye with the brain. ◦The optic nerve is also called the cranial nerve II.
•sclera
◦The sclera is the white, opaque portion of the eye. It provides protection and serves as an attachment for the extraocular muscles which move the eye. Know your eyes
Tears: The first line of defence, they also serve as lubrication by keeping the eyes moist and nourished; they also have a corrective lens function.
Eyelids: Their main job is to protect your eyes from dirt, dust and harsh light.
Eyelashes: A protective net for your eyes.
Cornea: A refractive zone that guides light to reach the retina.
Pupil: Controls the amount of light that enters your eyes.
Lens: A refractive zone that also guides light into the retina.
Retina and Optic Nerve: A bunch of intricate wiring that carries vision signals between your brain and eyes.
Special instructions to those who use computer excessively

• don't focus on a single object for a prolonged period of time;
• improve the lighting around your monitor;
• blink often;
• frequently close your eyes, then look far into the distance (down a hallway or out awindow) every 15-20 minutes to relax them;
• sit at least 18-28 inches away from the screen;
• tilt the monitor slightly below eye level; and
• keep your screen dust-free to minimize visual interference.