The effects of vision impairment as indicated by ( 1 ) near visual acuity , ( 2 ) contrast sensitivity , ( 3 ) self-reported cataracts and ( 4 ) self-reported other eye conditions ( e.g. , glaucoma , macular degeneration , diabetic retinopathy , optic neuritis , and retinopathy ) among participants randomised to either SPT or a social - and computer-contact control group was assessed .