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Multifocal contact lenses may reduce vision for night driving, at least among new lens wearers.
Older adults who wear multifocal contact lenses or monovision contacts to correct presbyopia may have greater difficulty driving at night than when wearing eyeglasses, according to a new study.
In an article published in Investigative Ophthalmology & Visual Science, researchers in Australia investigated the effect of a variety of methods of presbyopic vision correction on the night driving performance of 11 subjects between the ages of 45 to 64 years.
These methods were: 1) single vision eyeglasses for distance vision only, 2) multifocal eyeglasses with progressive lenses, 3) multifocal contact lenses, and 4) monovision contact lenses. Prior to the study, the only method of presbyopic vision correction the study participants used was reading glasses.
The different methods of vision correction were worn in randomized order, and measures of night driving vision performance included road sign recognition, low-contrast road hazard detection and avoidance, near target recognition, lane-keeping and driving time. For safety, all driving was performed on a closed-road driving circuit.
Study results showed:
- Study participants could see street signs quicker when wearing single vision and progressive eyeglasses than when wearing multifocal or monovision contact lenses.
- Participants had a reduced ability to recognize road hazards when wearing multifocal contact lenses.
- Participants drove more slowly when wearing multifocal contact lenses, compared with wearing eyeglasses with progressive lenses.
- Participants had more difficulty seeing dashboard instruments when wearing single vision eyeglasses.
“For those patients who drive long distances and hours at night, practitioners should carefully consider the best form of correction of presbyopia for these patients,” said study author Byoung Sun Chu, PhD, formerly of the School of Optometry, Queensland University of Technology in Brisbane. “One alternative is to prescribe the multifocal contact lenses for daytime use and a different correction for driving at night.”
The researchers recommended that additional studies with larger sample sizes be performed to confirm their findings and to determine whether the outcomes found in this study persist after multifocal and monovision contact lens wearers have more time to adapt to wearing the lenses for presbyopia correction.
“It is important that the results of this study are also used as a stimulus for improving the optical qualities of multifocal contact lenses to improve night time driving,” Dr. Chu added.
