Eye defects (AQA GCSE Biology): Flashcards
📚Flashcards
Practise the cards
15 cards from this deck
ShowHide
Practise the cards
15 cards from this deck
What are eye defects?
What are eye defects?
Problems with how the eye focuses light
Two most common eye defects
Two most common eye defects
Myopia and hyperopia
What is myopia (short-sightedness)?
What is myopia (short-sightedness)?
See close objects clearly, distant objects blurred
Where light focuses in myopia
Where light focuses in myopia
In front of the retina
Physical causes of myopia
Physical causes of myopia
Eyeball too long or cornea too curved
How myopia is corrected
How myopia is corrected
Concave lenses
What concave lenses do
What concave lenses do
Diverge (spread out) light rays
What is hyperopia (long-sightedness)?
What is hyperopia (long-sightedness)?
See distant objects clearly, near objects blurred
Where light focuses in hyperopia
Where light focuses in hyperopia
Behind the retina
Physical causes of hyperopia
Physical causes of hyperopia
Eyeball too short or cornea too flat
How hyperopia is corrected
How hyperopia is corrected
Convex lenses
What convex lenses do
What convex lenses do
Converge (bring together) light rays
What is a cataract?
What is a cataract?
Natural lens becomes cloudy/less transparent
Treatment for cataracts
Treatment for cataracts
Remove cloudy lens, replace with artificial lens
What is presbyopia?
What is presbyopia?
Age-related condition, lens becomes less flexible