Eye and head movement alterations in naïve progressive addition lens wearers

Abstract

Participants recruited more head movements for flash discrimination tasks and for reading text during adaptation to PAL wear. The many and various eye and head movement parameters analysed were unable to discriminate differences dependent on PAL design.

Comparison of progressive addition lenses for general purpose and for computer vision: an office field study

“…Furthermore, eye movements as well as gaze stabilisation take longer, while the wearer needs to find the area with the optimal focus for a given viewing distance during near and intermediate tasks . A narrow progressive zone may lead to larger horizontal head movements, when reading a line of text at near or intermediate distances; thus, the co‐ordination of eye and head movements is affected . This effect can decrease performance in visual tasks across larger horizontal visual fields .…”

“…Laboratory studies with controlled viewing conditions are useful to describe the optical and physiological mechanisms involved in presbyopic corrections. In addition, field studies are required to investigate the effects of lenses over a full working day in real office conditions to identify the possible implications on the subjective ratings of the viewing conditions, visual or musculoskeletal strain and ergonomic conditions.…”

How to place the computer monitor: measurements of vertical zones of clear vision with presbyopic corrections

“…The present results suggest that general purpose PALs can provide comfortable and clear vision in the vertical direction on a monitor that is placed sufficiently low and inclined backward and at the correct distance; however, the suitability of general purpose PALs for computer work may also depend on the horizontal field of clear view, which is limited by the progressive zone. The limited horizontal width of clear vision affects the patterns of the co‐ordination of eye and head movements when reading pages of text . Furthermore, the performance in the occupational task may be impaired.…”

“…These three examples illustrate that the type of lens must be selected primarily based on the user's task and that the monitor position must be arranged accordingly. Furthermore, the individual pattern of eye and head movements, the preference of clear distance vision or the practical issue of not changing glasses for distance vision, specifically for driving, could play a role.…”

“…The first limitation refers to the horizontal direction: clear vision for intermediate and near vision is only possible within a central vertical progressive zone, while astigmatic distortions are present in the left and right peripheral visual fields. As a consequence, the patterns of horizontal eye and head movements are modified . The second limitation of PALs refers to the vertical direction and is the topic of the present study, namely, to use the required addition for a given viewing distance, the inclination of the eye and the head must be adjusted, so that the visual line intersects the lens at the point with the required near vision addition.…”