The adjusted hazard ratios ( HRs ) for association of progression to cataract surgery at 5 years were : nuclear cataract increase of 1.0 unit or more compared with less than 1.0-unit change at 2 years , 2.77 ( 95 % confidence interval [ CI ] , 2.07-3 .70 ; P < 0.001 ) ; cortical cataract increase of 5 % or more in lens opacity in the central 5 mm of the lens compared with less than 5 % increase at 2 years , 1.91 ( 95 % CI , 1.27-2 .87 ; P = 0.002 ) ; and posterior subcapsular cataract increase of 5 % or more versus less than 5 % in the central 5 mm of the lens , 8.25 ( 95 % CI , 5.55-12 .29 ; P < 0.001 ) .