Sensory and Perceptual Changes Flashcards
1
Q
What are the general effects of aging on our senses
A
- There is a general decline in acuity
2
Q
Why does visual acuity decline with age
A
- Some are normal changes that occur with time/age
- Other’s can also be affected by several disorders that increase in prevalence with age, like cataracts
3
Q
Sclera
A
- White of the eye
- Protects and support the eye
4
Q
Cornea
A
- Surface of the eyeball
5
Q
Anterior Chamber
A
- Space between the cornea and lens
- Filled with aqueous humour, which is a water-like fluid
6
Q
Iris
A
- Changes the size of the pupil
7
Q
Lens
A
- Changes shape to focus light rays on the retina
8
Q
Viterous Humour
A
- Maintains shape of the eyeball
- Gel like fluid
9
Q
Retina
A
- Layer of tissue at the back of the eye that converts light into electrical signals for the brain
- Contains rods and cones
10
Q
Rods
A
- In the retina
- Used for night vision
- Eye contains around 125 million
11
Q
Cones
A
- In the retina
- Used in the day for colour
- Important for visual acuity/details
- Eye contains around 6 million
12
Q
The optic nerve
A
- Bundle of nerves that carries visual information from the retina to the brain
- Leaves the eye via the optic disc
13
Q
The optic disc
A
- Part of the retina at the back of the eye where the optic nerve begins
14
Q
What happens to the cornea with age
A
- The cornea becomes thicker and less curved
- Can cause Arcus Senilis which is a gray ring that forms around the edge of the cornea due to fat lipid deposits deep in the edge of the cornea
- Does not affect vision or need treatment
15
Q
What happens to the anterior chamber with age
A
- It gets smaller
- The fluid may drain inadequately, causing intraocular pressure and possibly glaucoma
- Doesn’t impair vision, so it doesn’t need much treatment
16
Q
What happens to the iris and pupil with age
A
- The iris colour fades
- The pupil diameter decreases
- Probably because the lens becomes thicker
17
Q
What happens to the lens with age
A
- Becomes less elastic, more dense, and more yellow
- This causes changes in colour vision and farsightedness increases
18
Q
What happens to the vitreous humour with age
A
- Becomes more liquid
- These loose cells can cause shadows/floaters in our vision
19
Q
What happens to the retina with age
A
- Vessels and capillaries narrow
- Loss and change in chemical sensitivity of rods and cones
- Can cause a decrease in visual acuity due to changes in refraction by cornea or lens
20
Q
Implications of vision loss
A
- Decreased accommodation ability meaning it’s harder to adjust to light and see
- Less light admitted due to smaller pupils
- Reduced number of rods and cones
- Decreased light/dark adaption
- Higher visual threshold meaning less light to stimulate receptors
- Increased sensitivity to glare
- Increased critical flicker fusion (how we can separate stimuli as different)
- Decrease ability to see close objects