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].|