Since the commercialisation of silicone hydrogel contact lenses in 1990s, major contact lens manufacturers have jumped on the trend of marketing silicone hydrogel contact lenses as being made with material that allows the highest oxygen permeability. As of 2015, the global market value of silicone hydrogel contact lenses is almost US$6.0 billion.
During its introductory stage, there was a hike in demand for silicone hydrogel contact lenses. Over the years, we have seen constant growth in this area; however, in recent years, the growth rate of silicone hydrogel contact lenses has slowed down. This is due to the high cost and low comfort level associated with the lens material. The plus side of silicone hydrogel is its high oxygen permeability, while the down sides are the stiffness of the lens, poor wettability and a tendency towards lipid deposits.
Source: Euromonitor International
Less silicone, more comfort
After being heavily marketed, manufacturers are now moving their focus towards a new generation of silicone hydrogel contact lenses. The stiffness of silicone hydrogel contact lenses means they are not that comfortable, especially in the case of people who wear them for more than eight hours a day. New generation silicone hydrogel contact lenses contain less silicone, therefore giving more comfort to the wearer, whilst still offering the same benefits as traditional silicone hydrogel contact lenses.
Two such examples of the new generation silicone hydrogels are Coopervision’s MyDay and Alcon’s Dailies Total1. MyDay lenses tap into a silicone technology that allows the company to blend the benefits of hydrogel and silicone hydrogel together. The outcome is a 4.4% silicone lens capable of bringing comfort, whilst being positioned as a high oxygen permeable contact lens.
Dailies Total1 uses water gradient technology; essentially, the material is a silicone hydrogel at its core, but it gradually moves to be a hydrogel-like surface. According to Alcon, with less than 1% silicone on the lens surface, this material is capable of bringing high oxygen permeability whilst offering comfort to the consumer, improving wettability on the lens surface.
The rise of hydrogel
While some manufacturers are moving towards less silicone, others are revisiting hydrogel, introducing premium hydrogel contact lenses instead. Premium hydrogel contact lenses are usually marketed at a lower price point than silicone hydrogel contact lenses. These lenses have increasingly being noticed by lens care practitioners and consumers in recent years.
In 2012, Bausch + Lomb first launched BioTrue ONEday in Europe, feathering unique HyperGel. This material offers higher water content and oxygen permeability than traditional hydrogel, without the need for silicone, according to Bausch + Lomb.
In 2013, Menicon introduced Miru 1day flatpack, poly (HEMA-GMA) material, offering a high wettability lens surface. Although the material is of lower water content, it exhibits a lower rate of evaporation rate when compared with material with higher water content, according to Menicon.
Essentially, the similarity of these premium hydrogel materials is the mimicking of the natural tear film which brings about hydration and comfort. In years to come, we will see more development in premium hydrogel material, which will drive up demand for hydrogel contact lens material. Consumers who are more health conscious will be more willing to upgrade to a contact lens material that allows their eyes to breathe with a lesser pocket pinch when compared with silicone hydrogel material.