Wearing regimes for contact lenses
Patterns of wearing fall into 3 types, overnight or extended wear daily wear and occasional wear. Within these are differing intervals between replacements, these being 3-monthly, monthly, fortnightly, and daily disposable, with longer intervals for complex and rigid lenses.
It is essential that lenses are kept free of dirt and debris and remain sterile due to the close proximity of the eye where infections can cause problems. These are usually minor and transient, but there are rare cases of more serious insult to the eye. The longer the interval between replacement the greater the need for specialist solutions to clean and sterilise the lens. This includes the regular cleaning and replacement of contact lens carry cases which can be breeding grounds for germs.
It had been hoped that daily disposable lenses would have reduced infection rates but it would appear that the less we have to do maintain our clean lenses, the less we bother with other hygiene issues when placing the lens in the eye. It may be a factor that many people wear the dailies who perhaps need greater comfort through more oxygen transmission and greater wettability perhaps through dry eyes. For most people therefore we would recommend seriously considering the new generation of silicone lenses. Undoubtedly, the reduction in overwear and oxygen debt problems by the new silicone hydrogels which are plasma treated for extra wettability, has created the new battle ground for market share with the larger manufacturers all positioning 2 weekly modality lenses.
There will always be wearers who can comfortably wear "one size" mass produced hydrogels without discomfort or outward signs of damage, but then why not take up the new technology for safer and better visual comfort. Many daily wearers also find that their lifestyle does not require regular daily wearing so moving to a less frequent modality will give better vision and a reduction in wastage.
The introduction of plasma treated silicones along with effective and simplified cleaning will provide a simpler answer to many with visual corrections and many would say at much less risk than invasive laser treatment on corneas.