👦 Orthokeratology (Ortho-K) Lens Simulator

Fitting the Reverse-Geometry Lens Before Sleep

A rigid gas-permeable lens is placed on the eye each night before bed.

• RGP: Lens material (Rigid gas-permeable)
• Nightly: Wear schedule (6–8 hours sleep)
• 8–12: Typical start age (Pediatric myopia onset)
• Reverse geometry: Lens design (Multi-curve back surface)

Lens fitting basics

Custom-fit lens flattens cornea using tear film hydraulics overnight.

Tear Film Pressure Flattens the Central Cornea

While the child sleeps, trapped tear fluid molds the corneal surface.

• ~1–2 D: Central flattening (Refractive change overnight)
• Epithelium: Cells affected (Reversible reshaping)
• 7–10 nights: Reshaping duration (To reach stable effect)
• Fully: Reversibility (Returns without lens use)

Overnight molding mechanism

Epithelial cells redistribute, thinning centrally and thickening mid-periphery.

Steepened Periphery Creates Myopic Defocus Signal

Central flattening plus peripheral steepening shifts focus in front of retina.

• Mid-periphery: Defocus location (Ring around fovea)
• Myopic: Defocus type (Focus falls short of retina)
• Sclera: Signal target (Growth-regulating signal)
• Clear: Central vision (Focused precisely on fovea)

Why peripheral defocus matters

Peripheral image location signals the eye to stop growing longer.

Comparing Treated and Untreated Axial Growth Over Years

Years of consistent wear slow axial elongation versus no treatment.

• ~0.38 mm/yr: Untreated growth (Typical pediatric myopia)
• ~0.15–0.25 mm/yr: Treated growth (With consistent wear)
• 32–63%: Reported slowing (Across published studies)
• Multi-year: Effect duration (Sustained with continued use)

Long-term elongation curves

Compliant multi-year wear produces the flattest elongation trajectory.

Consistent use over years shows the clearest control benefit.

Waking Up to Lens-Free Clear Vision

Removing the lens each morning leaves a temporarily reshaped, clear cornea.

• ~16/day: Lens-free hours (Full waking day)
• ~1–2 days: Correction duration (Fades without nightly wear)
• 20/20: Uncorrected acuity (With consistent wear)
• Sports, swimming: Activities enabled (No daytime lens or glasses)

Daytime outcome

Clear glasses-free vision persists until the next night of wear.