Employing a novel polymerisation technique together with using the highest purity monomers produces the Contaflex range of FDA approved soft contact lens materials. This results in a range of soft lens materials with water contents from 38% to 55% that exhibit zero stress and excellent machinability.
Each of the products has their own benefit, the lower water content materials have greater lens stability and higher tensile strength and suit daily wear applications. The mid water content materials offer a greater Dk that leads to more comfortable wearing characteristics and excellent clarity of vision.
Contaflex (FDA) technical information
Material Characteristics:
| Property | Polymacon 38% | Hefilcon 45% | Methafilcon 55% |
|---|
| Classification – (ISO 18369-1:2009) | Filcon l1 | Filcon l1 | Filcon lV 2 |
| FDA Approved | Yes | Yes | Yes |
| USAN | Polymacon | Hefilcon | Methafilcon |
| Ionic or non-ionic | Non-Ionic | Non-Ionic | Ionic |
| Swell Factor | 1.20 at 20°C | 1.27 at 20°C | 1.35 at 20°C |
| Water Content | 38% at 20°C
by refractometer
40% by weight | 48% at 20°C
by refractometer
46% by weight | 57% at 20°C
by refractometer
57% by weight |
| Refractive Index | 1.51 Dry
1.438 Hydrated | 1.52 Dry
1.42 Hydrated | 1.51 Dry
1.40 Hydrated |
| Light Transmission | >96% | >95% | >94.8% |
| Density | 1.27g/cm3
1.17g/cm3 Hydrated | 1.25g/cm3
1.13g/cm3 Hydrated | 1.28g/cm3
1.07g/cm3 Hydrated |
Oxygen Permeability (ISO)
X10-11(cm2/sec)
(mlO2)/(ml x mmHg) | 7.9 | 13.8 | 19.5 |
| Tensile Strength | 0.44MPa | 0.26MPa | 0.47MPa |
| Elongation to break | 136% | 165% | 140% |
| Hardness (Shore D) | 88 | 88 | 88 |
| Handling tints | Blue/Violet/Green | Blue | Blue |
| UV Blocker | On request | On request | On request |
| Diameter | 12.70mm | 12.70mm | 12.70mm |
| Thickness | 5.00mm | 5.00mm | 5.00mm |
Please note: These are typical values. Always check the certificate of compliance supplied with the goods for the actual values of the batch.
Diamond Tooling:
| Tooling | Radius (mm) |
|---|
| Rough | 0.30mm |
| Fine | 0.30mm |
Machining Recommendations:
| Lathe type | RPM | Bulk Cut | Fine Cut |
|---|
| Manual | 6,000 | 0.25mm | 0.10mm |
| CNC | 6,500 | 0.30mm | 0.10mm |
| Air Bearing | 9,500 | 0.30mm | 0.10mm |
Environment Control:
For best manufacturing conditions Contamac recommends 19-23°C with a relative humidity of 45%-60%.
Polishing:
The recommended polishing compound is Contapol 2 with a spindle speed of 3500rpm and minimal weight. With the above machining recommendations polishing should require a maximum of 30 seconds.
Hydration:
Hydration of the Polymacon and Hefilcon materials is best performed in buffered saline with a PH of 6.8 – 7.5.
To ensure complete hydration of lenses manufactured from our Methafilcon material, a two-step hydration process is required.
Step 1: Place the dry finished lenses in a pH 8.2 isotonic saline solution for a minimum of 15 hours, in a controlled environment at 20°C +/- 2°C.
Carbonate Buffered Saline pH 8.2 (1 litre) NaC1 (Sodium Chloride) 8.00 grams NaHCO3 (Sodium Bicarbonate) 1.25 grams
Step 2: Place the hydrated lenses into a pH 7.2 isotonic saline solution and store the lenses for at least 2 hours. The lenses will now have full total hydration and will be ready for final parameter measurement.
Borate Buffered Saline pH 7.2 (1 litre) NaCI (Sodium Chloride) 8.00 grams H3BO3 (Boric Acid) 2.47 grams Na2B4O7. 10H2O (Sodium Tetraborate decahydrate) 0.14 grams
Manufacturing Consumables:
- Contapol 2 polishing Compound
- C-15 White Blocking Wax
- Kemdent Blocking Wax
- C-18B White Brushed Cotton
- C-18C Beige Microfibre Cloth
Accessories
- Glass Vials
- Silicone Bungs
- Flip Tear Crimp Top Seals
- Horseshoe Crimp Top Seals
- Steel Hand Crimper
- Plastic Tweezers
- Shrink Wrap Sleeves