Parents Ask
Ortho-K vs. Defocus Lenses: an Honest Comparison for Parents
The two most proven optical ways to slow myopia. One is worn asleep, one is worn all day. Here is how to choose without the sales pitch.
How they compare
What it is: rigid lenses worn during sleep that gently reshape the cornea; clear vision all day with nothing on the eye.
Evidence: slows axial elongation by roughly 40–60% in studies — a long, solid track record.
Cost of ownership: strict nightly lens hygiene (rare but real infection risk), regular lens replacement, and higher yearly cost. Great for swimmers, athletes, and kids who refuse glasses.
What it is: ordinary-looking glasses whose lenslets create a "slow down" defocus signal for the retina.
Evidence: slows myopia progression by about 50–70% in RCTs when worn 10–12+ hours a day, with five-plus years of follow-up data and no rebound after stopping in the DIMS six-year study. In September 2025, the HAL design (Stellest) became the first eyeglass lens authorized by the US FDA to slow pediatric myopia progression.
Cost of ownership: no infection risk, no solutions, no nightly routine — but the effect depends on wearing time, all day, every day.
Five questions that settle it for most families
- Age and maturity: under about 8, or squeamish about touching eyes? Glasses win by default.
- Hygiene reality check: will an adult supervise lens care every night? If not, glasses.
- Sport and water: daily swimmers and contact-sport kids often love ortho-k's daytime freedom.
- Budget over 5 years: add up lenses, solutions, replacements and visits — ortho-k usually costs meaningfully more per year.
- The child's vote: the treatment they will actually wear beats the theoretically better one. Compliance is the active ingredient.
Whichever you choose, two rules don't change
First, optics alone are half the plan. Outdoor time and near-work habits (S1 and S2 in the 6S Method) multiply whatever the lenses do. Second, track the result. Every control method has non-responders — children whose eyes keep growing despite treatment. The only way to know which group your child is in is an axial-length measurement every 3 months, at the same clinic, on the same device. If the curve doesn't bend in 6–12 months, the plan changes — that's not failure, that's management.
Some children benefit from combining approaches (for example, adding low-dose atropine), but combinations belong in a doctor's hands — never self-prescribed.
Chosen? Now prove it's working.
Log each measurement and watch the curve bend — or catch it early if it doesn't.
Evidence base for this page (ortho-k and defocus-lens trials): #25 · #36 · #38 · #40 · #42 — full citations and DOI links in our Evidence Library.