Human factors Age and vision

Age and vision 20 Year old vision 60 year old vision

Population growth segment 75 year old - estimate, Grandpa hopes this is serious exaggeration!

Lens opening with age and time of day Day (mm) Night (mm) Difference 20 4.7 8.0 3.3 40 3.9 6.0 2.1 70 2.7 3.2 0.5 Source: visual expert.com

Contrast sensitivity _ increase need compared to 20 year old Visualexpert.com

Additional Visual impacts Glare Color Blindness Greens must be 1.3 times as bright as red to be equally visible (general population) Loss of field of vision Motion perception Mental processing

Human factors and signing Mental Processing Consider minds processing pattern in next slides

Aoccdrnig to rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoetnt tihng is taht the frist and lsat ltteer be at the rghit pclae

The rset can be a ttoal mses and you can sitll raed it wouthit a porbelm.Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef,  but the wrod as a wlohe. Amzanig, huh?

Human Factors notes Short term memory may be for only 5 to 15 seconds. Depends on: (class provide suggestions

Potential responses to question Urgency of the message Other messages to compete with the original message (information overload) Original understanding of the message Word versus symbol Visual versus audio - (audio is longer)

Recall presentation on Mnoady What were the digits that you were asked to remember? (Those went into short term memory only - and maybe not that well.) What was the concept or strategy used to help us remember the series of digits? My expectation: you will remember the strategy - where was that placed?

Mental processing time Data scattered here, but we do know that elderly have more difficulty with: Judging whether a rear-end collision will occur Judging correct speed Braking rapidly Steering smoothly Judging when to merge into traffic Judging when to turn corners

Good news Wisdom of age also means that the bulk of the elderly do make adjustments for their driving deficiencies. They Adjust speeds Choose time of day to minimize day / night problems Travel at off-peak times and travel less Avoid distractions (cell phones, partying passengers?) They are only somewhat over-represented by fatalities per population; it is in fatality per mile driven that peaks are most obvious.