Multifocal or bifocal glasses are glasses that contain both a distance prescription and a near prescription.
The top portion of the lens allows the wearer to see at distance, while the lower portion of the lens allows the wearer to see at near.
How does it slow down myopia?
Decreased ability to focus at near, otherwise known as a lag of accommodation, has been shown to play a role in myopia progression.
By providing a built-in near prescription, multifocal glasses supplement the amount of accommodation needed and reduces near blur/strain when performing near tasks such as reading or using the computer.
Similar to orthokeratology and multifocal contacts, the near prescription in a multifocal lens also produces myopic defocus, which inhibits ocular elongation.
Lined bifocals provide direct feedback to the child so they know if they’re using the correct portion of the lens to look up close or far away.
Especially helpful for children with esophoria (inward ocular alignment) who may already have reduced accommodative ability
Child could lose or break the glasses.
Social stigma around wearing bifocals as a child.
Lower efficacy compared to the other treatments available.