Dual-focus soft contact lenses can alter vision and accommodation. Photo: Maria K. Walker, OD.

While shown to be an effective strategy for myopia management, there is evidence that dual-focus soft contact lenses can alter visual quality and accommodative function. A recent study, which compared dual-focus and single-vision soft contact lenses, confirmed this to be the case. Therefore, eyecare providers should take these effects into consideration when determining the best approach for their myopia patients.

The study included 23 healthy soft contact lens wearers with myopia <-0.50D and astigmatism <0.75D. The researchers recorded steady-state accommodative response via the WAM-5500 binocular open-field autorefractor during the execution of a 10-minute psychomotor vigilance task at 50cm either with dual-focus or single-vision soft contact lenses. They performed each experimental session on two different days in counterbalanced order.

A greater lag of accommodation, variability of accommodation and reaction time was observed among individuals wearing dual-focus lenses when compared with single-vision soft contact lenses. The study authors reported mean differences during the 10-minute psychomotor vigilance task of 0.58±0.81D, 0.31±0.17D and 15.22±20.93ms, respectively.

These findings demonstrate that wearing dual-focus soft contact lenses negatively affects accommodation and behavioral performance during the execution of a 10-minute sustained visual task in the short-term, according to the study authors.

“These outcomes are of special relevance for practitioners when prescribing these lenses to slow myopia progression, especially in individuals who have demanding visual requirements,” they concluded. “Future studies are needed to assess the long term-effects of these lenses on accommodation and behavioral performance.”