What it means and why
Orthokeratology uses specially fitted rigid gas-permeable lenses to temporarily change the cornea’s shape. Many designs are worn during sleep and removed for daytime vision. The effect depends on the prescribed wearing schedule and is reversible; this is not a permanent removal of myopia.
Daytime clarity and changes in eye growth are different outcomes. Clinical use requires a specific fitting, hygiene plan and follow-up. Ordinary rigid or soft lenses cannot be made into ortho-k lenses by wearing them overnight.
A worked example
Teaching scenario: a wearer sees clearly without glasses after removing the lens. That is the temporary optical effect; it does not measure axial-length progression. Follow-up uses the relevant measurements, not just the number of hours of clear daytime vision.
What it does not tell you
Overnight use does not remove infection risk. Pain, redness, light sensitivity or reduced vision needs prompt assessment; do not continue wear simply to preserve the next day’s clarity.
THINK IT THROUGHDoes clear daytime vision prove that the eye has become shorter?
No. Corneal reshaping changes focus; eye length requires its own measurement.
Sources & reading notes
Page updated:
- FDA · Types of contact lenses ↗ Public health information
Useful for general health explanations and safety guidance; individual assessment and local advice still matter.
- CDC MMWR · Corneal infections associated with sleeping in contact lenses (2018) ↗ Public health information
Useful for general health explanations and safety guidance; individual assessment and local advice still matter.