Final Answer:
Light
enters your eye through a
transparent portion of the
sclera (the tough, white, outer covering of the eye), called the
cornea. The cornea is
curved, so it slightly
bends the light as it goes through. Light then passes through the
aqueous humor (a clear fluid used for
nourishment of the eye) and then through the
pupil.
The pupil is simply a
hole in the
iris. The iris is a
muscle that controls how
large the pupil is. It is the
colored part of the eye. In low light, the iris
relaxes and the pupil gets
larger; in bright light, the iris
contracts and the pupil gets
smaller.
Directly behind the iris is the
lens. This is the structure that can change
shape in order to
focus light so that we can see
clearly. Its shape is
convex, meaning it curves
inward on both sides. The
ciliary muscles above and below the lens control the
thickness of the lens.
Behind the lens is a clear gel called the
vitreous humor.
Light goes through this, then strikes the
retina. This is the
layer on the inside of the
back of the eye containing
two types of cells sensitive to
light:
rods and
cones. Rods sense
dim light and
motion and can work in
low light. Cones sense
color, and must have a certain amount of light to work.
Parent Tip: Review the logic above to help your child master the concept of structure of the human eye worksheet.
