According to Contact Lens Manufacturer and Ophthalmologists, the best way to clean contact lens is through physical rubbing. A typical contact lens user manual would suggest applying 1 or 2 drops of cleaning solution on the lens and hand rubbing gently with a circular motion for about 15 seconds. The manual rubbing process is proven effective in removing protein and lipid deposition on the lens, however it has its limitations.
Firstly, our fingertip is often larger than the lens. it is hard to reach the concave of the lens without distorting it.
Secondly, the manual rubbing process focuses on cleaning the inner side of the contact lens. However, since the eyelid coats the tear fluid on the outer surface of the lens when we blink and the moisture of the tear fluid evaporates, the outer surface of the lens collects more residue than the inner side. With the existing hand rubbing method, it is difficult to remove the residue on the outer surface of the lens.
Lastly, nails, calluses and dead skin could potentially damage contact lens. Wearing chipped or scratched lens could not only cause discomfort to your eyes but also scratch the front surface of the cornea and cause permanent eye damages.
Besides the limitations, hand rubbing contact lens is a tedious routine for many people. CDC research shows that between 40%-90% of contact lens wearers do not properly follow the contact lens care instructions. Approximately 99% of respondents reported hygiene behavior associated with an increased risk of eye infection.
Contact lens cleaning devices are invented to replace the manual rubbing process of lens care.
In today's market, there are 3 main types of contact lens cleaning devices --- physical rubbing, ultrasonic/vibration and UV light. Let’s talk about if they work and which one works the best.
This type of devices mimics manual rubbing. The lens is sandwiched between a silicone damping head and a lens cushion. The device removes all debris with a gentle, yet high speed rubbing action. VueSonic is the patented physical rubbing contact lens cleaning device. It is so far the only clinically proven effective and FDA cleared method to replace hand rubbing.
The vibrating devices use an eccentric motor to swing the solution that contains contact lens. Similarly, the ultrasonic devices theoretically clean lenses by the vibration wave in the cleaning solution generated by ultrasound.
These two types of cleaning instruments have limited cleaning efficacy because there is no relative motion between the lens and the solution. The lens moves following the flow of the liquid. However when combined with physical rubbing, the effect of vibration/sonic technology is maximized. VueSonic uses lower frequencies to break the bond between residue and the lens, and higher frequencies to increase the transmittance of the lens, and the dampen force on both side of the lens could easily 'wipe off' the residue.
UV light kills potential bacteria on the lens. However, UV light does not remove protein or lipid deposition which is the major cause of eye discomfort and complication. In addition, because our contact lens conditioning solution already features the function to sterile lenses, UV light is not necessary in the daily lens cleaning process.
In conclusion, physical rubbing contact lens devices are a helpful tool in the contact lens care routine. The most advanced version of VueSonic combines physical rubbing with sonic techbology. It is clinically proven to be more effective than hand rubbing in removing lens debris.