Development and Validation of a Disabling-Glare Mapping Device for Quantifying Dysphotopsia-Related Effects

Positive dysphotopsia (PD) refers to disturbing light phenomena, associated with spectacles, contact lenses, intraocular lenses, or refractive surgery, which reduce visual comfort and vision aid acceptance. Current methods lack high accuracy in quantifying the size and shape of PD. To address this issue, a mapping device was developed and validated.

Participants fixated a glare source centrally mounted in front of a 40" plasma screen (3 m distance) with one eye, under scotopic conditions. A white stimulus moved outward randomly in 36 directions from the central point. Upon it becoming visible, the participants pressed a button and the position was recorded. The set of positions forms a polygon representing PD size and shape. To determine measurement uncertainty, 10 repeated measurements were performed on six healthy participants (median age 23 years). To assess feasibility, measurements were performed in 18 participants (median age 22 years) wearing monofocal and multifocal soft contact lenses in random order.

Repeated measurements yielded a mean 95% confidence interval of the mean disabling glare area of ± 3.5 cm² (8% relative error; mean 44 cm²). The multifocal lens induced a 74% larger disabling glare area than the monofocal lens (92 ± 34 cm² vs. 53 ± 14 cm²; p < .001). The self-reported glare size was correlated positively with the measured disabling glare area (p < .02).

The dysphotopsia size and shape of two contact lenses were determined using a mapping device. The different optical designs could be discriminated. The measurement repeatability was within 8% error. This instrument is a potential assessment tool with applications in clinical practice, research and lens development.