The history of contact lenses

 
Contact lens help
Lens fitting and care
Lens insertion and removal
Contact lens disinfection
Contact lens protein removal
Lens solution incompatibility
Contact lens history
Contact lens future
Contact lens glossary
 
Types of contact lens
Soft contact lenses
Hard contact lenses
Disposable contact lenses
Extended wear contact lenses
Bifocal contact lenses
Contact lenses for astigmatism
Therapeutic contact lenses
 
Contact lens problems
Contact lens dry eyes
Damage to lenses
Contact lens infections
Eyelid inflammation
Corneal complications
Contact lens conjunctivitis
Giant papillary conjunctivitis
Peripheral corneal infiltrates
 
History of Contact Lenses

The famous and versatile scientist, Leonardo Da Vinci first introduced the general concept behind the invention of contact lenses. He was more concerned about knowing the mechanism of eye accommodation and explained how the power of the cornea can be changed by immersing the eye in a bowl of water. It was only after three centuries following this observation that contact lenses were manufactured and used.

After Leonardo, in the early years of the 17th century, Descartes proposed that corneal contact lenses be used to correct eyesight. His idea involved using a glass tube filled with liquid and a protruding end made of clear glass, which was to be positioned directly with the cornea. This was, however, impractical as it prevented blinking.

In the year 1801, Thomas Young built on Descartes’ proposal to correct his own vision by using a water filled tube of glass whose outer end was fitted with a microscopic lens and looked like an eyecup. However, this did not rectify the problems of light refraction.

The English astronomer Sir John Herschel came up with two ideas of a sphere of glass filled with animal jelly and making a mould of the wearer’s eye to fit exactly on the eye surface. However, Herschel never put his ideas to action and it was really Dr. Dallos who, much later, perfected the method of taking a mould from the wearer’s eye to correspond to the actual shape of the eye.

The forerunner of the contact lenses used today was was developed by a German named Adolf Fick who explained how afocal scleral contact “shells” could be placed on the less sensitive part of tissue surrounding the cornea. In 1887, he constructed and fitted the first ever workable contact lenses based upon this idea and these were made of heavy blown glass and covered the entire eye surface with the empty space between the cornea and glass filled with a sugar solution. As Fick’s lenses were large and cumbersome, it was Muller who came up shortly with a more manageable glass blown scleral lens.

Till the 1930’s, the above-mentioned scleral leses were the only type of contact lenses available. Following this, plastic scleral lenses were constructed for the first time with the invention of polymethyl methacrylate – better known as Plexiglass. William Feinbloom introduced the first American lenses where the centre was made of glass covering the cornea with an outer band of plastic covering the sclera. In 1945, the American Optometric Association acknowledged the fitting of contact lenses to be an important part of optometric practice.

In 1948, Kevin Tuohy started manufacturing contact lenses made entirely of plastic but still covering the entire cornea. However, in the later part of the same year, Butterfield modified Tuohy’s design by manufacturing lenses, which had flatter curves and closely corresponded to the corneal shape to sit better on the eyes.

Throughout the next two decades plastic corneal lenses were used, which were much smaller and thinner and were placed on the cornea rather than on the entire visible eye surface.

One of the major drawbacks of these PMMA lenses was that oxygen could not pass through the lens to the cornea thereby potentially resulting in serious side effects. Therefore, in the 1980’s and 1990’s rigid oxygen permeable materials or polymers were developed to counter this problem. These are hard contact lenses and, though continuous improvements were made to make these plastic lenses smaller and thinner, these were in general quite uncomfortable for many users.

In 1960, Otto Wichterle’s experiments led to the path-breaking discovery of the use of soft contact lenses made of a soft water resistant plastic, which were more popular than the conventional rigid lenses due to higher and more immediate comfort level. The approval of the soflens material by the United States FDA came through in 1971 and became available for commercial distribution by Bausch and Lomb. Today about 90% of contact lenses sold in the U.S are soft lenses.

In 1978, the first toric contact lens was also approved for commercial distribution and silicone acryalate lenses (RGP) were marketed in the next year. Over the next few years, extended wear soft lenses, bifocal daily wear soft contact lenses, tinted RGP lenses, extended wear RPG lenses, disposable soft contact lenses, planned replacement lenses, disposable tinted contact lenses, daily disposable lenses and first disposable lenses using ultra violet absorber became available in the U.S for commercial distribution.

Finally in 1999 there was the distribution of silicone hydrogels in the market. This coupled the advantages of high oxygen permeability of silicone with the extreme comfort and clinical excellence of hydrogels. These new lenses were originally only advised for overnight use, but are now used for prolonged, multi day wear as well.