Final Info- Ch.10 Aging Flashcards
pupil changes with age
pupil size decreases (miosis) due to iris dilator atrophy
effects of iris changes with age and mitosis
- increased depth of focus (DOF)
- decreased retinal illumination
the lens yellows with age, causing:
lose the blues, B-Y acquired tritan color defects possible
effects of lens changes with age
- increases in optic density from increased in axial dimension = decreased retinal illumination
- increased light scatter, reduces contrast of retinal images from opacities
2 conclusions about lens absorption changes with age
- less transmission for every wavelength
2. shorter wavelengths take a bigger hit
photoreceptor changes with age influence:
some age related loss may occur, but it is not responsible for a decline in visual acuity (thats from light)
examples of some age related loss to photoreceptors
- reduction in photopigment density
- possible neural changes like reduced convergence to bipolar and ganglion cells and decreased neurotransmitters
dark adaptation sensitivity changes with age and why
loss of overall sensitivity because rod photoreceptor loss and some rod outer seem bent enlargement
dark adaptation speed changes with age and why
adaptation rate is slower because slowed rate of rhodopsin regeneration (neural regeneration slower)
how is the decrease of high contrast visual acuity with age?
really robust- some decrease with age, but less than any other visual function (between 75-80)
does the difference between high and low contrast visual acuity change with age?
yes, larger difference between high and low contrast with age (around 70-75 yr old- difference is more than 13 letter average)
disability glare changes with age
gets worse (really fast) after 70 yrs old
recovery from glare changes with age
gets worse after 70 yrs old (lots of variability with older age too)
how many patients over 70 years old fail the D15?
~ 1/3 of patients
changes in spatial contrast sensitivity with age mostly affect what spatial frequencies?
losses at middle and high SFs
if measuring one spatial frequency, what is the age for decline of contrast sensitivity?
70
the most robust vision function is:
temporal vision CFF
temporal CSF reduction with age affects:
reduced at middle and high TFs
technically lower CFFs should decrease because it is:
dependent on retinal illuminance (Ferry Porter)
what motion change could be possible with age?
less accurate in judging direction of motion, 2nd order motion worse with aging?
what type of motion is more robust with age?
biological motion
visual field sensitivity and extent with age
lose sensitivity and extent with age, but it is not a huge change (same slopes in whole retina too)
how does the attentional VF decrease with age (compared to static VF)
definitely drop with age, especially after 70 yrs
how does useful field of view (UFOV) change?
- can decline in the presence of normal clinical VF
- declines with age
why does the useful field of view (UFOV) decline with age?
- reduced speed of visual processing
- reduced ability to divide attention
- reduce salience of the target against its background
what matters more: spatial contrast sensitivity or visual acuity?
spatial contrast sensitivity b/c facial recognition and falls/mobility issues
what has been found to correlate to accident rates?
UFOV
2 most robust visual functions?
- flicker (CFF)
- high contrast acuity
3 least robust visual functions?
- attentional field area
- glare recovery time
- vision in glare
