Macular degeneration is one of the leading causes of lost eyesight (results in a loss of your central vision field) in the elderly, and a new paper suggests the vigorous exercise could reduce this form of lost vision. With macular degeneration you retain peripheral vision, however the loss of the central visual field makes it difficult to recognize faces or read.
Williams 2008, ran a prospective study and followed more than 40,000 individuals over a 7 year period and found that higher level of running was associated with lower risk of age related macular degeneration (AMD).
After controlling for other influencing variables the risk for AMD decreased 10% for each km/day ran (for the non-metric aware people - for each .6 of a mile that was run each day risk of AMD was reduced by 10%).
So a simple 3 mile run each day would reduce your risk of this form of lost eyesight by 50%.
Another reason to go for your daily exercise (run, bike, etc) - to go along with:
running decreases the risk of dying - what else needs to be said - so make sure you keep moving
While this is obviously only a partial list of the benefits of running - you can now add decrease probability of one form of age related vision loss to this list.
So get out there and exercise today - no simpler brain and health hack than that.