The effects of long-term extended wear of soft contact lenses on human conjunctival and limbal vasculature were determined by examining 27 patients who had worn a high water content hydrogel contact lens in one eye only for an average of 62 ± 29 months (mean ± SD). The levels of general conjunctival hyperaemia (p > 0.01), limbal hyperaemia (p > 0.001), and the extent of limbal vessel penetration (p > 0.001) were found to be significantly greater in the lens-wearing eye, relative to the control eye, immediately on lens removal. The patients ceased lens wear for up to one month, and changes in the levels of vascular response were monitored during this period. General conjunctival hyperaemia and limbal hyperaemia recovered to levels observed in the non-lens-wearing eye within two and seven days after lens removal, respectively. However, limbal vessel penetration was still significantly greater in the lens-wearing eye 33 days after ceasing lens wear (p > 0.05).