The history of glass and plastic lenses

“The
Beginning”
The
development of contact lenses is an old story, dating back to 1500 –
1508.  The first insight into the treatment of optical defects of the
cornea with a device is given to the great Italian, Leonardo da Vinci. 
Master Leonardo filled a bowl with water, then placed a man’s face into
it.  It is said that for the first time the individual was able to see
clearly.  There are two very important factors about this discovery. 
Improved refraction and improved peripheral visual
acuity.     

Leonardo
da Vinci also made a contact lens with a funnel on one side so that water could
be poured into it.  Of course, this was immediately discarded due to
impracticality. 
In
1636, after reviewing Leonardo’s work, a French scientist, Renee Descartes, in
a special medical treatise, Ways of Perfecting Vision, described a concept of a
lens placed directly onto the eye.  He developed a tube he could fill with
water and place directly against the cornea. This was also impractical and
discarded.    
We
must remember that early technology did not make it possible to develop and
manufacture devices that would fit directly on the eye and produce good
vision.  That being the case, spectacle lenses were the only devices used
to correct vision.  Patient’s with regular corneas and normal astigmatism
had very good vision. Individuals with corneal astigmatism or diseases and
abnormalities of the cornea had minimal visual improvement with glasses. 
Wearable contact lenses did not begin to evolve until the nineteenth century.
In 1801,
Thomas
Young described a neutralizing surface for the cornea that was the forerunner
of contact lenses.  Sir John Herschel, the English astronomer and
physicist, wrote and circulated an opinion that corneal contact lenses were, in
fact, optically feasible.  Herschel was also the first to suggest
that an actual mould of the cornea might be taken. 
These
ideas though, lay dormant for approximately sixty years.  His suggestions
were theoretically sound but very problematic due to practical applications
that were too difficult to overcome.  One of the barriers was the need to
make a mould of the sensitive corneal tissue.  The cornea is totally
avascular, with thousands of nerves, making a very sensitive tissue.  With
the introduction of anesthesia in 1884, contact lens technology advanced because
moulding was made possible. 
In
the early 1880’s, glass contact lenses that fit the anterior of the eye, called
scleral lenses, were invented by Adolf Fic, Eugene Cult and August Mueller,
independently.   Dr. Fic was a physician in Zurich, Switzerland, who
wrote a treatise entitled A Contact Spectacle, in which he described the first
contact lens with a refractive power, to protect the eye and later for visual
improvement.  This first lens was made by F. A. Mueller in 1887, a manufacturer
of artificial eyes. 
Fic
also recognized a method for correction of different types of irregular
astigmatism other than spectacle lenses, which did not adequately correct the
refractive power of irregular corneas.  This device to neutralize the
refractive power of the cornea, consisted of placing a small glass bowl directly
on the eye, much like Leonardo had done 300 years prior.   Later, Fic
prepared a set of trial glass lenses.  Fic selected the diagnostic lens
that was most suitable for each of his experimental subjects.  These
original contact lenses were made of very thin glass.  
Fic
used these lenses quite successfully in treating patients with corneal disease
and abnormalities. These abnormalities, such as keratoconus, can cause scarring
and a definite  obstruction to the refraction of light.  Fic’s lenses
were quite successful compared to other applications but were still cumbersome
and uncomfortable.       
Cult,
who was a glass blower from Wiesbaden, Germany, described another method by
which keratoconus could be corrected by suppression of the cone and correction
of the refraction with glass shells.   
Over
the course of about sixty years, scleral lenses made of glass were the major
contact lenses used.  Scleral glass lenses were primarily manufactured by
Carl Zeiss Company in Jiena, Germany,  as early as 1912.
Making Progress
In
the 1930’s, the availability of plastics produced lenses that were lightweight
and very transparent.  They were chemically consistent, stable,
unbreakable, scratch resistant and much easier to manufacture.  This
eventually changed the course of contact lens technology. 
In
1937, Theodore Obrig developed manufacturing techniques for making plastic
lenses and suggested the use of fluorescein dyes to study the morphology of the
lens fit against the patient’s cornea.  With the introduction of
polymethylmethacrylate (PMMA) a flush fitting scleral lens was made
possible.     A few Labs still fit and manufacture these
types of contact lenses for the treatment of severe keratoconus disease and
Stevens-Johnson syndrome.
The
therapeutic use of these lenses was developed by Woodly in England in
1954.  These lenses also had desirable cosmetic effects.  Innovations
greatly contributed to the success of contact lenses, for both cosmetic and
therapeutic use.  
The Beginning of the Renaissance
An
optician from England, Kevin Touhy, introduced the corneal lens, which covered
only the transparent portion of the protective coating of the eye (the cornea)
in 1947.  The lenses, patented by Touhy in 1948, rested directly against
the limbal margin of the cornea.  These lenses had diameters of 10.80 to
12.50 mm.  They were much more attractive and easier to wear than the
glass and plastic scleral lenses that preceded them. 
Many
changes were rapidly introduced to these types of lenses until a product
emerged that was safer and could be worn all day, had tremendous optical
clarity and was invisible to the human eye.  These changes allowed early
contact lens patients to address the public with confidence.  The new
contact lenses could be worn in all kinds of weather and were useful for
sporting activities of all kinds.  Because the contact lens was large, but
smaller than earlier scleral lenses, it was not easily dislodged or lost.
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