Use of Single-Vision Distance Spectacles Improves Landing Control during Step Descent in Well-Adapted Multifocal Lens-Wearers

Abstract

Use of single-vision distance spectacles led to improvements in landing control, consistent with individuals' being more certain regarding the precise height of the lower floor level. This enhanced control was attributed to having a view of the foot, step edge, and immediate floor area that was not blurred, magnified, or doubled and that did not suffer from image jump or peripheral distortions. These findings provide further evidence that use of single-vision distance lenses in everyday locomotion may be advantageous for elderly multifocal wearers who have a high risk of falling.

Prismatic displacement effect of progressive multifocal glasses on reaction time and accuracy in elderly people

“…Timmis et al’s work suggests that participants wearing single vision glasses had more control when stepping down from a block height when compared with individuals who were well adapted to multifocal lenses 9. The study compared kinematic mechanics in 20 older people and found that those participants wearing single vision glasses had reduced vertical center of mass velocity, increased single-limb support time, and reduced peak ankle and knee angular velocities.…”

Optical characteristics of Alvarez variable‐power spectacles

“…Changes in oblique astigmatism have also been found to be associated with increased dizziness in patients after cataract surgery, while the orientation‐dependent spectacle magnification associated with larger, particularly oblique, induced cylinder powers may cause gait and other difficulties . Nevertheless, when considering the possible acceptability of current Alvarez spectacles and their astigmatism from the point of view of safety, it must be remembered that progressive lenses, particularly those with higher additions, show very substantial amounts of astigmatism on either side of the narrow progressive corridor and that the use of such lenses, and of other forms of spectacle multifocal, is accepted, in spite of the higher rates of falls and other problems that older wearers of such lenses experience in comparison with the wear of single‐vision lenses . The advantages of the multifocals in terms of the improvements in vision that they offer over a range of distances are judged to outweigh the disadvantages of spatial distortion and consequent accidents, and similar compromises might be justifiable in the case of the small levels of unwanted astigmatism in Alvarez lenses.…”

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

“…The acceptance of progressive lenses in everyday vision can depend on the optical lens characteristics and on individual eye movement characteristics . The blurred and distorted vision through the peripheral and lower parts of the lens can affect the perception of steps and may lead to more variable foot positioning and an even higher risk of falling . 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 .…”

“…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.…”