Influence of vision distance and lens design in presbyopic user preferences

The objective of this study was to determine the parameters that influence the subjective assessment of progressive addition lenses (PALs). An initial field study was carried out to distinguish the main factors (refractive error, occupation, distance of vision) that have an influence on PAL preference. The results obtained from this initial phase were used to design a preference and laboratory test in which three similar PALs were compared. The results showed that laboratory studies are more efficient than preference tests or field studies for comparing PALs with a similar design philosophy. It was also shown that, regarding PAL user preferences, the design of each vision zone has a different influence. Further research will be carried out to examine in greater detail the reasons for the differences among subjects’ preferences. The comparison between three different methods used in this work permits selection of the adequate procedure and the optimal experimental design to assess PAL preferences depending on the aim of the study.