Designing for the Life Span Segment 3

Slide 66 Content

Summary Conclusions - Vision Change:

There are multiple changes to vision occurring more frequently with age but some such as visual acuity change independent of the aging process;
Accommodation to lighting levels changes with age - with older adults requiring higher levels of lighting to perform visual tasks such as reading;
Adaptation to varying light levels slows with age, generally an individual at 70 adjusts to a light level change three times slower than someone who is 25;
With growing opacity of the lens, older adults have a greatly increased sensitivity to glare;
The human eye is a "camera" device that focuses light in the eye to see edges of objects - a "figure/ground" relationship;
The human eye possess a variable capacity to see different colors... reds better than greens and both reds and greens far better than blue;
Figures formed in blue light will be the hardest to see - especially blue text on any ground that is not a large block text;
The human eye gradually and naturally looses the ability to see blue light;
The combination of vision changes that occur with age alter behavior - especially in complex environments, for example: the aging driver slows down the car in order to handle adaptation, glare and information processing necessary to perform the driving task successfully.