A recent randomized, double-masked crossover study took a closer look how multifocal (MF) and monovision (MV) presbyopia contact lenses distort light—and how patients handle the adaptation. The researchers studied 20 presbyopic patients who wore either MF or MV contact lenses for 15 days. After a one-week washout period, they switched lens type. Each modality was tested for induced photic phenomena such as dysphotopsia, glare and halos.

After evaluating the light distortion and subjective quality of vision in both monocular and binocular conditions, the researchers found the distortion increased in all parameters in both modalities. However, after 15 days of lens wear, the distortion parameters decreased significantly in the MF lens wearers, more so than in the MV wearers. The Quality of Vision questionnaire showed no significant changes with either contact lens modality.

“Adaptation to light disturbances induced by MF CL is more effective compared to MV,” the researchers conclude. “Practitioners will have greater success if they prepare their patients for the adaptation required as their vision will get better and have less of an issue with light disturbance.”