This is a study of the physiological function of the eyes at night. However, the risk of automobile injury or fatality (driver, passenger or pedestrian) associated with motor vehicle accidents has been determined to increase with age, as a result of the complex interplay of age-related declines in vision, motor and cognitive functioning. However, basic visual function is the foundation for higher order processing whether it is visual spatial or cognitive. Four recent studies reflect the cost of poor vision on driving. (www.visionimpactinstitute.org). For example, visual impairment among European drivers was examined in 2422 drivers from 5 European countries. Visual acuity, visual field, contrast sensitivity, glare sensitivity, and useful field of view were tested. Visual functions not included in the current licensing standards were found to be more impaired among drivers (compared to those functions legally required). Elderly drivers are particularly vulnerable to sensory visual impairment when driving at night, as they suffer declines in both Contrast sensitivity (CS), Glare Disability (GD) and Glare Recovery (GR).6~Justification for study involving humans~Carotenoid science is well developed with respect to the safe utilization of dietary lutein (L) /zeaxanthin (Zx) as studied by the National Institute of Health (NEI). The recently published NEI AREDS2 study- May 2013, further substantiated the safety and usefulness of prescribing the carotenoids (10 mg L / 2 mg Zx) in patients at high risk of AMD. 7 Significantly, the average American and veteran population are typically low dose consumer of these carotenoids (1 to 2 mg/day for the average American).
Vision at twilight and night is more difficult and dangerous for the entire population, even more so for the elderly and especially for the elderly with degenerative disease. Multiple worldwide laboratories have demonstrated the ability to raise macular pigment optical density with dietary carotenoids. This proposal further evaluates the relationship between macular re- pigmentation and vision under stressed conditions simulating twilight and night driving.