Visual Defects Flashcards
Match:
- myopia
- hypermetropia
- long-sighted
- short-sighted
Myopia - short-sighted
Hypermetropia - long-sighted
Does hypermetropia result in light being focused before or after the retina?
after the retina
What lens is used to correct hypermetropia?
Convex (+ve)
What lens is used to correct myopia?
Concave (-ve)
What type of visual defect is at an increased risk of retinal detachment?
Myopia
When viewing near things is the lens more relaxed or contracted?
Contract - fatter - contract the ciliary body
What is the name for the increase in long-sightedness in adults as they age?
Why does this occur?
Presbyopia
Ciliary body doesn’t contract as well as used to -> unable to accommodate for close-up work
Why does astigmatism occur?
What is astigmatism?
How is it corrected?
More oval lens -> 2 focal points
Distorted and blurred vision at any distance
Cylindrical lens
What does long-sighted mean?
Can see things far away but not close up
Is a negative lens a thick or thin lens?
Thick lens
Negative used to treat myopia -> need concave lens
Define the following terms:
- Emmetropia
- Ametropia
- Anisometropia
Emmetropia - no refractive error
Ametropia - some refractive error (light either focused in front or behind retina)
Anisometropia - difference between refractive errors
Match the following: Myopia Hypermetropia Closed angle glucoma Open angled glucoma
Myopia - open angle glucoma
Hypermetropia - closed angle glucoma
In manifest squints what can be noted about the corneal reflections?
Corneal reflections are carried out by shining a pen torch into patients eye
They will be asymmetrical
What is a cover test?
What is it used for?
To find/confirm manifest squint
Cover eye and observe other eye - if got a squint uncovered eye will move to correct position e.g. exotropia squint would move inward to be more central
Match the following names of squint to presentation:
- Exotropia
- Esotropia
- Hypertropia
- Hypotropia
Exotropia - outward
Esotropia - inward
Hypertropia - upward
Hypotropia - downward
Horizontal double vision is associated with …tropia and …tropia.
Vertical double vision is associated with …tropia and …tropia
Horizontal = esotropia and exotropia
- problem with LR/MR
Vertical = hypertropia and hypotropia
- problem with SO, IO, SR, IR
Where would a pathology be in a patient who is presenting with homologous hemianopia with macular sparing?
Occipital lobe - due to multiple blood supplies to macula
A child with a suspected squint is tested using the cover test. The affected eye is covered and then the patch removed and the opposite eye is covered instead. The affected eye moved inward when uncovered. What kind of squint does this suggest?
Inward movement suggest it was outward when covered = EXOtropia
Describe how the retinal reflex will appear in those with squints?
Off centre
At what age are the neural pathways for the eye fully developed?
8 yo - treatment has to begin before this
