The Human Eye Flashcards
Where is the Pupil and what is it’s function.
The pupil is the small hole in your eye that allows light to enter in the eye.
What is the Iris?
The iris is the colored part that controls the light sensitivity. The Iris opens or closes around the pupil to let more or less light in as needed.
What is the Cornea?
The cornea is a thin, transparent tissue that covers the front of the eye. Light refracts on the cornea and the lens, which focuses light towards the retina.
What is the Retina?
The retina is the tissue at the back of the eye containing rods and cones. The rods are sensitive to light who’s main function is to adjust light at night. The cones are responsible for detecting color.
How do we see?
The Cornea first refracts light, then the lens, which will focus it on the retina. The image will be smaller and inverted, but when it travels to the brain, the image is corrected.
What are some focus problems?
Farsightedness (Hyperopia) is the inability to see close objects clearly, with the image being produced behind the retina. Glasses with convex lenses are used to fix this by shortening the focal length so the image is produced on the retina.
Nearsightedness (Myopia) is the inability to see far objects clearly, with the image being produced in front of the retina. Concave lenses are used to diverge light rays and thus extend them to the retina.
