Ophthalmology Physiology Flashcards
What is presbyopia?
Eye has reduced ability to focus on near objects because of age
What is emmetropia?
No refractive errpr
What is hypermetropia?
Long-sightedness
What is myopia?
Short sightedness (eye is larger)
What is astigmatism?
Not a perfectly curved lens, leads to blurriness
Name extra-ocular muscles?
Medial rectus (CN III) Lateral rectus (CN VI) Inferior rectus (CN III) Superior rectus (CN III) Superior oblique (CN IV) Inferior oblique (CN III)
What muscle and nerve does looking up test?
Superior rectus/Inferior oblique
CN III
What muscle/nerve does looking up and latreally test?
Superior rectus
CN III
What muscle/nerve does looking laterally test?
Lateral rectus
CN VI
What muscle/nerve does looking down and laterally test?
Inferior rectus
CN III
What muscle/nerve does looking down test?
Inferior rectus/Superior oblique
CN III/CN IV
What muscle/nerve does looking down and medially test?
Superior oblique
CN III
What muscle/nerve does looking medially test?
Medial rectus
CN III
What muscle/nerve does looking medially and up test?
Inferior oblique
CN III
Where are cones mainly situated?
Fovea
Rods are not where?
Fovea
What produces the aqueous humour?
Ciliary body
What is the usual intra-ocular pressure normally?
<21mmHg
What is consensual response?
Light shining in on eye causing constriction of the pupil (direct response) and in the other eye (consensual response) so both eyes contract
What does PS innervation to the pupil cause?
Constriction
What type of drugs constrict the pupil?
Miotics
eg pilocarpine
What does sympathetic innervation cause?
Dilation
Which type of drugs dilate pupil?
Mydriatics
eg tropicamide, atropine
What is definition of keratitis?
Infection of cornea
