Distance from the patients eyes to the ETDRS visual acuity chart:Len:Pt:^Patient:Qn:PhenX
distance from the patients eyes to the etdrs visual acuity chart:len:pt:^patient:qn:phenx
Distance from the patients eyes to the ETDRS visual acuity chart:Length:To identify measures at a point in time:^Patient:Quantitative:PhenX
distance from the patients eyes to the etdrs visual acuity chart:length:to identify measures at a point in time:^patient:quantitative:phenx