Orthokeratology
Material properties of contact lens
Jan 31st
General nature
1. Transparency
2. Hardness and toughness
3. Tensile and strength
4. Elastic modulus
5. Relative density
6. Refractive index
7. Wettability (surface tension, wetting angle, water absorption)
Special nature
1. Moisture content
2. Ion charge
3. Permeability (Dk value, Dk/L or Dk/t, EOP)-3.0D
Am I suitable for orthokeratology?
Jan 29th
Who is suitable for orthokeratology?
Indications
1. Get the understanding of the mechanism of the correction, potential problems and limitation of the correction.
2. Good motivation and compliance
3. Myopia arrange from -0.75d to -6.00D, astigmatism lower than 1.75D, with rule.
4. Corneal curvature arranges from 37D to 52D.
Contraindication
1. Have unrealistic expect.
2. Ocular diseases such as infection and so on.
3. Refractive error more than -6.00D, anti rule, astigmatism more than 2.0D
4. Age less than 12.
5. Not compliance.