Previous studies have suggested a link between poor vision and death, yet the exact causal connection has remained elusive.  Michael J. Karpa, from Westmead Millennium Institute (Sydney, Australia), and colleagues examined 3,654 persons, ages 49 and over, during the two year period of 1992 to 1994, and after 5 and 10 years. The team assessed each subject for visual impairment and calculated their associations with mortality risk based on Australian National Death Index data.  The researchers found that the study subjects with vision problems that couldn't be corrected were 35% more likely to have died during the 13-year study period.  Further, those with uncorrectable vision problems and were less than 75 years of age were more than twice as likely to have died.  The team speculates that difficulty walking is a probable causal connection between poor vision and early death.  Those who don’t walk well or much may not have good access to healthcare, be socially isolated, and make poor lifestyle choices based on lack of mobility.  In addition, trouble walking may limit the ability to engage in routine physical activity and also contribute to an increased number of falls and injuries.