MYTH: Undercorrection will slow down myopia
It is common that parents and even some practitioners has a believe that giving full correction or full powered glasses, the eyes will adapt and take in more power in the future, leading to myopia progression.
The recent major review on myopia interventions done by all major experts in myopia from all over the world. The review was done on studies that were well powered (good sample size) and well designed (randomized controlled trial) as listed in the table above.
Below are the findings:
1) Under correction was found to be significantly worse than full correction in 2 cohort studies at 20.7% and 29.8%
2) The other 2 studies did not find any difference between full correction and under correction.
With the possible risk of worsening vision by about 20% by reducing 0.50D (50 degrees) and having to suffer poor vision (2 lines below 6/6). It seems like myth for under correction is busted! In fact, Chung et al, 2002 had to terminate the study in advance as the myopia progression for under correction was too severe to be able to continue.
As such, it is advisable to have full correction and to update your prescription every 6 months for kids and 1 year for adults if the changes were 0.50D or more.
Reference: Christine F. Wildsoet, Audrey Chia, Pauline Cho, Jeremy A. Guggenheim, Jan Roelof Polling, Scott Read, Padmaja Sankaridurg, Seang-Mei Saw, Klaus Trier, Jeffrey J. Walline, Pei-Chang Wu, James S. Wolffsohn; IMI – Interventions for Controlling Myopia Onset and Progression Report. Invest. Ophthalmol. Vis. Sci.2019;60(3):M106-M131. doi: 10.1167/iovs.18-25958.