By Jackie Muise
The quest to improve vision through an artificial lens that actually makes contact with the surface of the human eye has been a determined pursuit for more than 500 years, beginning with Da Vinci’s rudimentary looking through water experiments to today’s research into surgically implanted Bionic Lenses – promising to one day render vision three times better than 20/20 regardless of age or infirm.
Between those two extremes, however, the average modern day contact lens wearer has bene tted from improvements to contact technology by a developmental re- naissance of sorts over the last 60 years, accelerating at an astounding rate during just this past decade. It’s a progression that has taken us from glass lenses cover- ing the entire surface of the eye, to various synthetic plastic materials covering only the cornea (the clear eye-tissue over the iris and the pupil), to the very latest in electronic “smart-lens” technology.
Today, in addition to a huge range of re- placement options, everything from daily to annual, contact lenses fall into two fundamental categories: soft lenses that are made from moisture holding, pliable plastics; or the “breathable” gas permeable (GP) contact lens made of a sturdier, less bendable plastic. The GP’s are also known as RGP’s, or Rigid Gas Permeable, although they should not be confused with the now nearly obsolete hard lenses.
Both categories o er a range of designs to accommodate many kinds of vision issues and both have their advantages and dis- advantages. The custom tted considered the choice for corrective, sharper vision, are longer lasting and less likely to harbour bacteria.
They also have been known, however,
to be more di cult for the wearer to get used to. And of course, whatever the reason for choosing contacts – vision correction, convenience or cosmetic – none of those three motivations is likely to over-ride an uncomfortable, irritating t. In answer
to that problem, and for many who have been told in the past they were not good candidates for contacts, there is the new “scleral” GP contact.
Scleral GP’s are larger in diameter than both the conventional GP or soft lenses, covering more of the whites of the eye. This larger size makes them more secure, as well as more comfortable than the older type GP’s while still retaining all the ben- e ts of the gas permeable material.
The scleral GP’s come in three di erent sizes and, according to the educational branch of the Opticians Association of Canada (OAC), they are particularly help- ful for those who have hard to t eyes, dry eyes or irregular corneas.
“Irregular corneas come in many shapes and sizes, sometimes caused by things like keratoconus (thinning, cone shaped cornea) or laser surgery,” says Sandra Blanchette, optician and spokesperson for the OAC, “… soft contact lenses will not always do the trick in correcting vision. A sclera lens is made of RGP materials, vaulting the cornea and correct- ing the patient’s vision by making a new corneal surface.”
Not to be outdone by developments in the GP contact industry, soft lens manu- facturers have now encroached on the traditional purview of gas permeables. In the fall of 2015, Cooper Vision, launched a daily disposable product made of 4.4 per cent silicone hydrogel material that not only offers the comfort and adaptability of conventional soft lenses but has incor- porated the health bene ts of an oxygen permeable contact.
In January 2016, Johnson & Johnson announced the market success of their recently released “daily disposable moist multifocal”, a soft lens that o ers a solution to the presbyopicneeds (diminished ability to focus on near objects) of aging consumers.
The real cusp of contact lens development, however, appears to lie not so much in the ever-evolving kinds of materials that contacts are made from, but the electronics that, by all indications, will soon be embedded
In 2014, it was announced that Alcon would be partnering with Google in the development of “smart lens” contacts. These particular “smart lenses” will be equipped with sensors that can do things like monitor glucose levels through the eye uid of diabetic patients and/ or automatically near-focus for surgically implanted cataract lenses.
Mark Smithyes, Head, Communications, Government A airs and Marketing Access for Alcon Canada Inc., says the company is honoured and excited about the partnership.
“Our part is to provide the clinical expertise and development for this very rst medically applied contact lens technology,” says Smithyes from his o ce in Toronto, “and we are on trackto start clinical trials before the end of 2016.”
In addition, the Electronic Contact Lens (ECL), reported by the Florida-based company, E-Vision Smart Optics, will also be prototype ready by the end of this year.
The ECL is designed, through the use of “an electric eld surrounded by a layer of liquid crystal material”, to render the contact elec- tronically adjustable “on the y”in order
to accommodate near, far or intermediate viewing situations encountered by individual ECL wearers.
Whatever the future of contacts, the good news is – here and now – there is virtually something for everyone in contacts.
By Jackie Muise