Performance: Lecture 5 - Light and Elderly

Question 1

3 effects of age on clear vision

Answer 1

Ability to focus is harder
Limited scattering in eye
Transmittance through the eye changes

Question 2

Optical changes with age

Answer 2

Amplitude of accommodation decreases
Limited scattering resulting in blurry images
Pupil diameter becomes bigger
Yellowing of lens leading to lower transmittance

Question 3

By what three things is visual acuity influenced?

Answer 3

Contrast
Luminance
Glare sources

Question 4

Spectral absorbance of lens increases or decreases with higher wavelength?

Answer 4

Spectral absorbance decreases with higher wavelengths

Question 5

Does CCT affect visual acuity?

Answer 5

Yes,at 200 lx a significantly better performance for higher CCT (blue light)
For young age groups it does not really matter

Question 6

Mention three neural changes related to age

Answer 6

Processing of signals to visual cortex slower
Density of rods and cone photoreceptors decreases
Number of neurons in visual cortex and ganglion cells decreases

Question 7

From what age onwards does the need for light in reading tasks increase a lot?

Answer 7

40

Question 8

What does not change with increasing age?

Answer 8

Vernier acuity —> seeing two lines parallel

Specific colour vision like wavelength of unique hues (primary and secondary colors are still visible)

Question 9

Effects on visual functions in elderly (example images with stairs:)

Answer 9

1. Cataract –> issue with lens. Overall blurry image
2. Diabetic retinography –> issue with retina. Do not see colours (blood vessels broken)
3. Macular degeneration –> issue with fovea. Blurry spot in part of image
4. Glaucoma –> optical nerve. Multiple black spots

Question 10

Effects of ageing eye are: reduced ……

Answer 10

vision

• ability to focus, visual acuity
• scattering in eye
  
  • glare sensitivity

sensor and signal transmittance
color discrimination
- contrast sensitivity
    - resolution
    - luminance contrast
visual field

Question 11

What is the effect of daylight exposure on sleep efficiency?

Answer 11

Efficiency is higher when exposed to higher light intensities during the day

Question 12

Do elderly people have seasonal depressions?

Answer 12

No only a veeeery small amount of elderely does. But do have normal depressions for which they use light therapy

Question 13

Visual vs non image forming effects for elderly

Answer 13

Visual

• Worse visual performance
• Risk of falling
• Problems orientation
• Performing tasks takes longer
• Contrast and luminance sensitivity

Non-image forming effects

• Biological clock
• Sleep and wake cycle
• Winter depression
• Performance and alertness

Question 14

Light related symptoms in combination with dementia

Answer 14

Insomnia
Restlessness
Wandering
Declining social skills

Unable to live in own environment