A recent pilot study compared subjective and objective vision of children wearing single-vision and +2.00, +3.00 and +4.00 D add power soft multifocal contact lenses to determine whether the higher add power—which was thought to provide better myopia control—resulted in visual compromise.

Myopic children were assigned in random order to wear omafilcon A single-vision or multifocal “D” contact lenses with each of those add powers for one week each. High-contrast distance and near visual acuity, low-contrast distance visual acuity and contrast sensitivity were measured at each visit along with a quality of vision questionnaire to assess their vision. The Friedman test was performed to evaluate the impact of add power on all outcome measures.

All three multifocal lenses resulted in reduced contrast sensitivity compared with single-vision lenses. +3.00 and +4.00 D add lenses resulted in worse glare/starbursts, ghost images, computer vision, changing fixation distance and overall vision, but results varied. There were no differences among the lenses with respect to subjective assessments of distance vision, near vision, strain or tiredness, contact lens comfort or sporting activities.

The authors noted that even though these differences are statistically significant, they were “rarely clinically meaningful.”

“There were no differences among the lenses with respect to high-contrast distance visual acuity, and thus, visual complaints may not be identified when solely testing high-contrast distance visual acuity,” the authors explained in their study. “Instead, low-contrast distance visual acuity measurements may provide an explanation for visual complaints experienced with these lenses. In addition, asking patients about the quality of vision in real-life low-contrast situations (playing sports, driving, or viewing street signs at dawn, at dusk or in the evening) is important when considering whether an adjustment in the add power in a soft multifocal contact lens is necessary.”