GCSE Biology (AQA)
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Homeostasis and Response
The Human Nervous System
Myopia & Hyperopia
1:53
The Eye
Spec
4.5.2.3
- Two common eye defects are shortsightedness (myopia) and longsightedness (hyperopia).
- In myopia, objects near the eye are clear, while distant objects appear blurry.
- In hyperopia, close objects appear blurry, while distant objects are clearer.
- Both conditions occur when light does not focus correctly on the retina.
- Sharp vision requires light to be perfectly focused on the retina.
- The brain flips the image received on the retina to correct the orientation for our vision.
- In myopia, light is over-refracted, causing images to focus in front of the retina.
- In hyperopia, there is insufficient refraction, causing images to focus behind the retina.
- Causes of these conditions include variations in the length of the eye or the thickness of the lens or cornea.
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