Ocular and visual symptoms associated with accommodative and binocular vision stress have become a major problem as a result of digital eyestrain, especially in young individuals. Researchers recently discovered that using low-add soft contact lenses reduced accommodation response time, without sacrificing distance vision, in young, non-presbyopic patients.

This prospective single-blinded study included 16 participants who were evaluated with a daily disposable low-add bifocal lens. The design used a center-distance optical zone and a peripheral zone with an add power of +0.50D to support near vision. Monofocal soft contact lenses were used as controls.

The team measured refractive state and accommodation using an open-field autorefractor with three target vergences: -0.20D, -2.50D and -4.00D. They also assessed binocular visual acuity at high (100%) and low (40%, 20%) contrasts and reading ability.

They found that accommodative response with low-add contact lenses was significantly smaller than that with monofocal contact lenses at 40cm (2.50D of stimulus) and 25cm (4.00D of stimulus). The 20% contrast visual acuity at distance was significantly better with low-add contact lenses and second-time monofocal contact lenses compared with first-time monofocal contact lenses. The team noted that reading ability was not significantly different.

Koh S, Inoue R, Sato S, et al. Quantification of accommodative response and visual performance in non-presbyopes wearing low-add contact lenses. Cont Lens Ant Eye. July 19, 2019. [Epub ahead of print].