Refractive Errors Flashcards
1
Q
What is myopia?
A
Short-sightedness
2
Q
What is hyperopia?
A
long-sightedness
3
Q
What is astigmatism?
A
Non spherical curvature of the cornea or lens
4
Q
What is presbyopia?
A
Long-sightedness of old age
5
Q
What is meant by shortsightedness and what is the most common cause?
A
- Close objects look clear and distant objects appear hazy
- Eyeball too long
6
Q
List some of the symptoms of myopia
A
- Headaches
- Infants: divergent squint
- Toddlers: loss of interest in sports/people and more interest in books and pictures
- Teachers may notice child losing interest in class
7
Q
How can myopia be corrected?
A
Biconcave lenses
- Spectacles
- Contact lenses
- Laser eye surgery
8
Q
What is meant by hyperopia and what are the most common causes?
A
- Close objects look hazy and distant objects appear clear
- Eyeball too short or cornea + lens too flat
9
Q
List some symptoms of hyperopia
A
- Eyestrain after reading/working on the computer in a young individual
- Convergent squint in children/toddlers (needs immediate correction with glasses/lenses to preserve vision in both eyes and prevent a lazy eyes)
10
Q
How can hyperopia be corrected?
A
- Biconvex glasses
- Contact lenses
- Laser eye surgery
11
Q
What is meant by astigmatism?
A
Close and distant objects appear hazy
12
Q
How can astigmatism be corrected?
A
- Cylindrical glasses
- Laser eye surgery
- Toric contact lenses
13
Q
Describe what causes presbyopia and how it can be corrected?
A
- With age the lens gets less mobile/elastic
- So when the ciliary muscle contracts it doesn’t change shape as much
- This means that near objects/reading can be difficult to read
- Corrected by biconvex reading glasses
