·AIM:To observe the difference of corneal and conjunctival epithelial changes between normal subjects and subjects with long-term soft contact lens(SCL)wear(>5 years)and to probe the possible effects and mechanism on ocular surface with long-term SCL wear among university students.·METHODS:In this study,fluorescein vital staining(FLS),conjunctival imperssion cytology(CIC)changes of long-term SCL wearers were used.The study included 198 eyes of 99 SCL wearers and 70 eyes of 35 subjects as control group.SCL wearers were divided into three groups of less than 5 years and 5 to 10 years and more than 10 years according to the duration of contact lens wear.The differences of FLS、goblet cell density(GCD)and grade of squamous metaplasia were analyzed.·RESULTS:There were statistical differences in FLS,GCD and grade of squamous metaplasia between the control group and the groups wearing SCL(P<0.01);There were statistical differences in GCD and grade of squamous metaplasia between the group wearing SCL for of less than 5 years and 5 to 10 years and more than 10 years(P<0.01);but there were not statistically differences in GCD and grade of squamous metaplasia between the group wearing SCL for 5 to 10 years and more than 10 years;There were positive correlations between grade of squamous metaplasia and FLS(r=0.589,P<0.01);but negative correlations between GCD and FLS(r=-0.351,P<0.01).·CONCLUSION:Long-term and extended wear SCL caused the corneal epithelial injury,and CIC changes,the longer wear,the greater the damage.There are significant correlations between GCD or CIC grading and FLS.GCD and CIC grading can be used to assess the ocular surface conditions of long-term and prolonging SCL wear.·