Study finds, Differences in Visual Performance with Spherica
This study aimed to determine the maximum add power children wearing center-distance soft multifocal contact lenses could accept objectively and subjectively.

Myopic children were assigned in random order to wear omafilcon A single-vision or multifocal “D” contact lenses with +2.00, +3.00, or +4.00 D add power for 1 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.

--11 subjects were enrolled, and 9 subjects completed the study. The median age of completed subjects was 11 years.

--Median logMAR low-contrast distance visual acuity was reduced in the +3.00 and +4.00 D add lenses compared with the +2.00 D add and single-vision lenses.

--All three multifocal lenses resulted in reduced contrast sensitivity (+1.35 to +1.40) compared with single-vision lenses (+1.60).

--In general, +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.

In comparison to single-vision lenses, the +3.00 D and higher add powers cause more objective and subjective vision-related issues, but the +2.00 D add multifocal lenses were well tolerated.