ISO and ANSI standards, which describe requirements for operations like contrast sensitivity (CS), influence clinical evaluations of intraocular lenses were used to guide clinical research. The effect of glare on CS was frequently examined but was not standardized. ISO/ANSI recommended a glaring intensity that lowers mesopic CS by 0.1 log units at 6 cpd, as established by tiny pilot research, although the unclear criterion may result in variable glare levels between manufacturers.
Enrollees were 40-year-old healthy young people with a vision of at least 20/20. Mesopic CS at 6 cpd was assessed at 2.5 meters in 39 people using the Clinical Trial Suite (CTS, M&S Technologies) and in 20 people using the CSV-1000 (Vector Vision). The glare strength was adjusted to be the same for both devices (CTS:150 lux; CSV:12 lux, both before a 1.5 ND filter). The CTS was also used to assess two attenuated glare levels (69 and 110 lux).
Under typical glare strength, the mean reduction in CS was 0.16log units for CTS (95% CI 0.05, n=29) and 0.09log units for CSV (95% CI 0.08, n=12). The reduction in CS assessed with the CTS under attenuated glare was 0.14 (95% CI 0.06, n=20) and 0.15 (95% CI 0.05, n=24) log units for 69 and 110 lux, respectively, both over the 0.1 log unit threshold. According to the findings, various criteria were employed to calibrate the glare strength of both systems, resulting in a 12 fold variation in strength. As a result, clinical data received from various systems may not be comparable.