Neuro - Visual system Flashcards

1
Q

What are all of the different parts that make up the eye?

A

Lateral:

  • Upper eyelid
  • Palpebral fissure
  • Lateral canthus
  • Lower eyelid

Medial:

  • Pupil
  • Iris
  • Sclera
  • Medial canthus
  • Caruncle
  • Limbus
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2
Q

What structures make up the lacrimal system?

A
  • Lacrimal gland
  • Punctum
  • Canaliculus
  • Tear duct
  • Tear sac
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3
Q

What are the 4 layers of the tear film?

A
  • Lipid
  • Water
  • Mucin
  • Epethelial
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4
Q

What is the function of the tear film?

A
  1. Maintains smooth cornea-air surface to supply the cornea with oxygen
  2. Removal of Debris
  3. Bactericide
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5
Q

What is conjunctiva?

A

Thin, transparent tissue that covers the outer surface of the eye

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6
Q

What is sclera?

A

The tough, opaque tissue that serves as the eyes protective outer coat
‘The white of the eye’

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7
Q

What is the cornea?

A

The transparent dome covering the front of the ye used to refract light and focus light

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8
Q

What is the uvea?

A

The vascular coat of the eyeball which lies between the sclera and retina

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9
Q

What is categorised as central vision?

A
  • Detail day vision

- Colour vision

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10
Q

What is categorised as peripheral vision?

A
  • Shape
  • Movement
  • Night vision
  • Navigation vision
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11
Q

What is Emmetropia?

A

The refractive statem of the eye which parallel rays of light are focused on the retina to produce a clear image

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12
Q

What is Ametropia?

A

A mismatch between axial length and refractive power so parallel rays of light do not fall onto the retina

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13
Q

What is myopia?

A

Parallel rays coverge before they reach the retina

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14
Q

What are the symptoms of myopia?

A
  • Blurred vision

- Headaches due to trying to focus

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15
Q

What are the treatment options for myopia?

A
  1. Correction with diverging lens (negative lenses)
  2. Correction with contact lens
  3. Correction by removing the lens to reduce refractive power of the eye
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16
Q

What is hyperopia?

A

Parallel rays of light converge past the retina

17
Q

What are the symptoms of hyperopia?

A
  • Unable to see close objects/fine print
  • Asthenopic symptoms:
    • Eyepain
    • Headache in frontal region
    • Burning sensation in eyes
    • Blepharoconjunctivitis
18
Q

What are the treatment options for hyperopia?

A
  1. Correction with converging lens (positive lenses)
  2. Correction with positive lens and cataract removal
  3. Correction with contact lens
  4. Correction with intraocular lens
19
Q

What is astigmatism?

A

Parallel rays come to focus 2 focal lines rather than a single focal point

20
Q

What can cause an astigmatism?

A

The refractive media is not spherical

21
Q

What are the symptoms of astigmatism?

A
  • Asthenopic symptoms (headaches, eyepain)
  • Blurred vision
  • Distortion of vision
  • Head tilting and turning
22
Q

What are the treatment options for astigmaitsm?

A
  1. Regular astigmatism - cylinder lenses with or without spherical lens
  2. Irregular astigmatism - rigid cylinder lenses, surgery
23
Q

What is presbyopia?

A

Naturally occurring loss of nearsightedness due to increased rigidity of the lends and increased stiffness the ciliary muscle

24
Q

What are the treatment options for presbyopia?

A

Convex lenses

25
Why do both eyes get visual field affects if there is a lesion to the optic nerve posterior to the optic chiasma?
This is because 53% of nerve fibres cross over at the optic chiasma and go the go to the opposite eye, so a lesion will affect the opposite eye also
26
What type of nerve causes pupil constriction?
Parasympathetic nerve of CN III
27
What type of nerve causes pupil dilation?
Sympathetic nerve of CN III
28
What is the difference between a direct light reflex and a consensual light reflex?
A direct light reflex if the constriction of the the pupil of the light stimulated eye A consensual light reflex is the constriction of the pupil of the opposite eye to the one being stimulated
29
What are the 6 ectraocular muscles and the 3 cranial nerves that innervate them?
``` 6 extraocular: - Lateral rectus - Medial rectus - Superior rectus - Inferior rectus - Superior oblique - Lateral oblique 3 cranial nerves: - Cranial nerve III - Cranial nerve IV - Cranial nerve VI ```
30
What is duction
Eye movement in one eye
31
What is version?
Simultaneous movement of both eyes in the same direction
32
What is vergence?
Simultaneous movement of both eyes in the opposite direction
33
What is convergence?
Simultaneous adduction movement in both eyes when viewing a near object
34
What is saccade?
Short fast burst eye movement
35
What is smooth pursuit?
Sustained slow eye movement
36
What is a nystagmus?
Oscillatory eye movement | Optokinetic nystagmus - oscillatory eye movement + fast phase reset saccade