Paragon CRT / CRT Dual Axis (orthokeratology)
Paragon (CooperVision)
Manufacturer / labParagon (CooperVision)
Product / familyParagon CRT
DesignReverse-geometry overnight corneal reshaping lens; Corneal Refractive Therapy sigmoidal return-zone geometry. Dual Axis adds an independent toric landing zone
Corrects / indicated forMyopia (temporary reduction for spectacle-free daytime vision) and myopia progression control in children
Materialpaflufocon B (Paragon HDS) / paflufocon D (Paragon HDS 100); Paragon Z CRT uses tisilfocon A (Menicon Z)
Dk100 ×10⁻¹¹ (material)
Overall diameter10.5 mm (11.0 available)
Optic zone6.0 mm treatment zone
Centre thickness~0.16 mm
Power rangecorrects up to ~-6.00 D myopia and ~-1.75 D astigmatism (label); Dual Axis for higher WTR/ATR toricity
Wear scheduleovernight (worn while sleeping, removed on waking)
ReplacementAnnually
Fitting approachFit from Return Zone Depth (RZD) and Landing Zone Angle (LZA) using the CRT slide rule / calculator and refraction; assess the morning topography bull's-eye pattern and centration. Central island or smiley/frowny patterns drive RZD/LZA changes.
FDA-approved for overnight wear and (as a CooperVision myopia-management tool) supported by the strongest ortho-K evidence base. Emphasise nightly hygiene and hydrogen-peroxide disinfection, Acanthamoeba and microbial keratitis are the key risks.
Verify parameters against current manufacturer documentation before fitting.