The concept of the contact lens was described by Leonardo da Vinci in 1508. Lacking the technology to realize his idea, the first contact wasn't created until centuries later.
"They used to take molds of the eye, like dental molds," explains
Dr. Greg Gemoules, optometrist and owner of Laserfit Vision. "A
plastic impression was taken, and then the lenses were thermal
formed to conform to the shape of the eye mold."
A prototypical lens dating back to the 19th century, scleral lenses were originally made in the same fashion. Engineered from a
ridged lens material, the lenses are not technically "contact lens-es," in that they do not make contact with the corneal surface. This
unique property makes them ideal for individuals with diseased,
injured, or otherwise defective eyes.
Falling into disuse because the materials were not oxygen permeable, the scleral lens lost popularity until the technology's resurgence in the 1970s with the development of rigid gas permeable
"The modality of this lens fell into the background until someone
applied new RGP materials to the lens, thereby making it healthier
and setting the stage for its comeback," explains Gemoules.
Digital processes have since replaced molds for a more precise fit, improved vision, and comfort, a process for which Dr.
Gemoules has multiple patents pending.
In contrast to the trial lens or empirical method that involves a
kit of lenses made for the average eye (or the antiquated use of
molds) Gemoules' method makes use of advanced imaging systems.
"Eyes are diverse, so we needed an image-based approach," says
Gemoules. "Unfortunately, there was no imaging system specifically for scleral lenses."
To overcome this challenge, Gemoules turned to optical coherence tomography (OCT), a non-invasive imaging test that uses
light waves to take cross-section pictures. A process analogous to
an ultrasound, OCT uses light instead of sound.
"OCT devices are making huge inroads into medical diagnostics,
not just for eyes, but for other parts of the body," he explains.
Following the development of the technology, Gemoules brought
a loaner unit into his office to test its ability to scan the eye. "I
thought that it might work … and it did. That was the beginning of
The process begins by using a topographer to create a map of
the cornea. A ray-tracing wavefront aberrometer then provides
a detailed analysis of the eye. After a number of OCT scans are
taken, they are assembled into 3D model using CAD software (U.S.
patent 7,862,176 and other patents pending).
By Melissa Fassbender, Associate Editor
Photo: Carl Zeiss
The fluorescein pattern of the lens on the eye.
Photo: Dr. Greg Gemoules.