Vision problems

This document contains information and diagrams showing the process or how people see... and how to correct vision problems for long and short sighted people.

HideShow resource information
  • Created by: Sophie
  • Created on: 23-04-11 13:25
Preview of Vision problems

First 156 words of the document:

What happens in a person's eye, which has normal vision?
1. Like in the diagram above light enters the eye through the cornea, which is the clear surface that covers
the front of the eye.
2. The light then passes through the pupil.
3. The light then hits the lens, the transparent `structure' inside the eye that focuses light rays onto the retina,
to create an image.
4. Next, the light passes through the virtuous humour/body, the clear, jellylike substance that fills the core of
the eye and helps to keep the eye round in shape.
5. Finally, light rays reaches the retina, the lightsensitive nerve layer that lines the back of the eye, where the
image appears wrong side up.
6. The image is sent to the optic nerve, which is then responsible for turning the impulses it receives into
images.
By Sophie Page 9 Hildegard 4

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Long sighted:
The technical name for this is Hyperopia vision. Most people call it long sighted or farsightedness. This condition
makes close objects appear out of focus and may cause headaches and/or eye strain. Here is a diagram to show
Hyperopia:
It can be corrected with glasses or contact lens, by adjusting the focusing power to the retina. Corrective surgery
may also help by changing the shape of the cornea to a more round shape instead of an oval shape.…read more

Page 3

Preview of page 3

Here's a taster:

Short sighted:
This is the opposite of Hyperopia. This is commonly known as Short sighted, or nearsightedness. The proper
name for it is Myopia. It causes you to see close objects clearly and far away objects unfocused. Here is a
diagram to show how it works differently to other vision:
It can be corrected with the same methods as Hyperopia, just using a different shaped lens, like this one...…read more

Comments

Tanaz

Hi! This document was very helpful.. thank you

Similar Biology resources:

See all Biology resources »See all resources »