9.2 Flashcards

1
Q

What is the cornea?

A

A clear window at the front of the eye which allows light to enter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is special about the shape of the cornea?

A

Its shape allows it to function as a fixed focusing device. Responsible for 70-80% of the total focusing ability of the eye.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the eye and the pupil?

A

The size of the iris can vary to control the amount of light that enters the eye.

The pupil is the dark area at the centre.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the lens and why is it important?

A

It adjusts the level of focus.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When is the lens thickest and thinnest.

A

The lens is thickest when looking at a near object.

It is flattened when looking at a far object.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What effects accommodation (the lens)

A

Age and fatigue.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the retina.

A

A complex layer of nerve cells at the back of the eye connected to the optical nerve.

Contains two types of light sensitive cells: cones and Rods.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are cones and how are they different from Rods?

A

Cones function in good light.
Cones can detect fine detail.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Rods.

A

Rods cannot detect colour.
Good at detecting movement in peripheral vision.
Cones are in the centre of the retina and rods are in the peripherals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The fovea?

A

A small depression at the centre of the retina that is rés poi le for central vision

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does visual acuity mean?

A

The ability to discriminate sharp detail at varying details.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is hypermetropia?

A

Long sightedness.

Shorter than normal eyeball
Lens is shorter than normal.

Objects nearby will appear blurred

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of lens is used to correct hypermetropia?

A

Convex lens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is myopia?

A

Short-sightedness.

Eyeball is longer than normal.

Image is formed in front f the retina.

Distant objects will appear blurred.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are other forms of visual problems?

A

Cataracts - clouding of lens (age related)

Astigmatism - misshapen cornea

Glaucoma - a build up in pressure of the fluid

Migraine - severe headaches, distort vision.

Presbyopia - loss of lens flexibility (age related)

Fatigue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Influence of foreign substances on vision.
(Drugs)

A

Reduces supply of oxygen to eye which can affect the sensitivity of the rods.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How long does it take foe cones and rods to adjust to changing lighting conditions.

A

7 minutes for cones

30 minutes for rods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is colour blindness called

A

Colour vision deficiency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What % of people are effected by colour vision deficiency

A

8%of men

0.5% of women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Can age affect colour vision?

A

Yes due to yellowing of the lens.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

CAP 563 Leaflet H-60

A

Use of glasses or contact lenses is suitable if prescribed for an engineer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the three divisions of the ear

A

Outer

Middle

Inner

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Outer ear

A

The part of the ear that directs the sound along the auditory canal and into the eardrum.

24
Q

Middle ear

A

Sits in the eardrum, transmits vibrations.

Made of three small bones called hammer, anvil, stirrup.

25
Q

Inner ear

A

Filled with fluid.

Connected to the cochlea which contain hair like cells which react to the movement of the fluid and send of neural responses

26
Q

What are aural reflex muscles.

A

Can reduce loud noises by 20db.

No protection to sudden explosive noises.

27
Q

What range of frequency can a young person typically hear

A

20 - 20,000 Hz

Sensitivity peaks at 3000, Hz

28
Q

Impact of noie on performance

A

Annoying others.

Interfering with communications

Causing fatigue and effecting concentration

Damage hearing.

29
Q

What are regulations related to noise and hearing.

A

Employers must provide hearing protection if needed.

Employees have legal right to work without exposure to dangerous noise levels.

30
Q

Two types of hearing protection, and how much protection the provide.

A

Ear plugs, ear defenders.

Noise levels are reduced by 20dB and 40dB respectively

31
Q

Signs of early hearing loss.

A

Conversations become difficult or impossible.

You find it difficult to process sounds like “d” “t”

Permanent tinnitus.

32
Q

Noise dose.

A

Any sound over 80dB over an 8 hour period

Any noise over 115 for even short period of time.

33
Q

What is the process of information processing

A

Receiving information through the senses

Analysing information

Deriving meaning from the information

Storing information.

34
Q

Iconic memory

A

Provides a smooth stream of visual information to the brain which can be extracted over an extended period of time in the visual short term memory.

35
Q

Presbycusis

A

Hearing loss with age

36
Q

Echoic memory

A

Registers sound, once a sound Is heard it is stored in the echoic memory where it can be processed and understood.

37
Q

What are the forms of attention.

A

Selective attention

Divided attention

Focussed attention

Sustained attention

38
Q

What is “attention”

A

The brain function that alllocates cognitive processing resources to focus on information or stimuli.

39
Q

Selective attention.

A

When a person is monitoring several sources of input but focuses on the source that seems ore important

40
Q

Divided attention

A

Divided attention is common in most work situations, where people are required to do more than one thing at a time

41
Q

Focussed attention

A

Simply channeling your attention towards a single source and avoiding distraction.

42
Q

Sustained attention.

A

Is the ability to maintain concentration and remain alert over long periods of time. Usually on one task.

43
Q

What can perception be defined as?

A

the process of assembling sensations into a usable mental representation of the world

44
Q

What are the three processes of memory

A

Encoding, storage, retrieval.

45
Q

What is encoding (memory)

A

The input of information into the brain

46
Q

3 types of memory.

A

Sensory memory

Short-term memory

Long-term memory.

47
Q

Sensory memory

A

Ultra-short memory.

Consists of brief sensory events such as sights, sounds and tastes.

Very brief, up to a few seconds.

48
Q

Short term memory

A

Takes information from sensory memory and sometimes connectes that memory to something.

49
Q

Long term memory.

A

Used to store information no longer in use

50
Q

Two types of long term memory

A

Semantic memory
General facts

Episodic memory.
Events

(Motor programmes
Driving a car)

51
Q

What is retrieval

A

The act of getting information out of memory storage and back into conscious awareness.

Decision making is bases on retrieval and past experiences.

52
Q

What is situation awareness

A

The synthesis of n accurate and up-to-date mental model of ones environment and state, and the ability to use this to make predictions about ones future state.

53
Q

The influence of expectation.

A

Our perceptual system can reject irregularities, for example when skim reading you wont notice subtle changes in a text that you think you know well.

54
Q

What is claustrophobia

A

Fear of enclosed spaces.

55
Q

What is acrophobia

A

Fear of heights