The eye contains several key parts that work together to allow vision. Light enters through the cornea and pupil, and is focused by the lens onto the retina. The retina contains light-sensitive cells that transmit signals to the brain via the optic nerve. Nearsightedness occurs when the eye is too long, causing images to focus in front of the retina, while farsightedness happens when the eye is too short and images focus behind the retina. These conditions can be corrected using lenses or refractive surgery like LASIK. Other eye conditions include glaucoma and cataracts.

1. How can eyesight
Sarah
What is the eye ?
When light hits an object it bounces and reflects into your eyes,
your eyes have there own light bending parts called the lens and
cornea. The lens and cornea focus light into your retina. The cornea
is the outer part of the eye, collecting the light thats bouncing off
objects, it focuses light through a whole quite small. The iris is the
colored part of the eye, and your pupil is the black spot we have at
the center of our eyes, if it is dark the pupil will expand to let as
much light in as possible, so you can see better. Behind the pupil is
the lens, the part of the eye that focus light onto the back of your
eyeball the lens is clear and curve, it can also change it shape
depending on what you are focusing on (its kinda like the lens on
your camera). On the back of your eye is a layer of “tissue” called
the retina, it is covered in photoreceptive nerve cells, there are
cones and rods, rods and cones are sensitive to light, but only rods
can detect color. So the lens projects an image onto your retina,
where the rods and cones transform the light and color into electrical impulses. these are transmitted to the optic
nerve in your brain, then your brain decodes an image and then you can see !
Farsighted eyesight
Nearsighted eyesight
Other people’s cornea focuses the image behind
Certain peoples corneas are not shaped correctly, the retina which means they are farsighted,
so they focus the image in front of the retina, when things will look clear far but blurry close, using
that happens images look blurry, that means you convex lens are used in this case.
are nearsighted. Putting a concave lens on your
eyes will re-focus the light on your retina.
How do we cure these
changes ?
How do these changes occur ? Some people choose do LASIK eye surgery, where the
doctor uses a laser to reshape your cornea, after the
Some people are born with these problems where
surgery the cornea will focus the light close enough
right at there birth there corneas are not shaped
to retina. Some people just wears glasses and goes to
correctly and are either born nearsighted or
an eye doctor every year or few years, depends on
farsighted, some people have both nearsighted and
there condition. There eye doctor treats them,
farsighted eyes where one eye is nearsighted and the
changing there glasses degree because your eye
other far this is called astigmatism. In other cases, if
degree changes whether it gets better or worse.
you stare at something for too long and continue to
do it, you have a chance of getting nearsighted, for
example staring at your computer screen 24/7, and
look really close, you will have a chance of becoming
nearsighted. But with farsightedness you can only get
it naturally.
How can you protect your eyes ?
Some things we can do to protect our eyes are ;
wear sunglasses and hats on bright days, don’t
watch t.v. or computer for too long or your eyes
will get hurt, never look directly to the sun for
more then 3 seconds it is very dangerous, and
Are there any other eye last of all don’t wear other peoples glasses.
changes ?
Of course, besides nearsighted and farsighted
there is, Glaucoma - Glaucoma is a disease
characterized by damage to the optic nerve, a
nerve in your brain it can seriously interfere with
you vision. Another change is called Cataracts it
means when the lens of your eye becomes
cloudy.
Farsighted