In 1956, aspheric ophthalmic lenses for subnormal vision were developed by Dr. David Volk and manufactured by American Bifocal Co., of Cleveland Ohio. Dr. Volk found that an aspheric surface corrected the aberrations present in more common spheric lenses. These new aspheric lenses provided a substantial, undistorted visual improvement in a patient’s field of vision. These lenses were exhibited at the American Medical Association meeting.
The following year, a series of 10 aspheric subnormal vision lenses were developed, manufactured and again exhibited at the American Medical Association meeting. These lenses served as a basis for the development of aspheric indirect ophthalmoscopy lenses.
In 1974, Volk Optical/Tech Optics Inc. was formed and began commercial manufacturing of aspheric lenses, including the indirect ophthalmoscopy lenses. In 1982, all Volk lenses for indirect ophthalmoscopy which had been previously manufactured with one aspheric surface, were redesigned with both surfaces aspheric. This provided a substantial improvement in image quality.
Still in 1982, the double aspheric 60 Diopter lens became available for indirect ophthalmoscopy on premature babies and newborn infants. That same year, Claes Lundberg, in Sweden, reported on the use of the Volk 60D lens for indirect ophthalmoscopy with the slit lamp biomicroscope.
This successful use of the 60D lens led to the development of a series of indirect ophthalmoscopy lenses by Volk Optical, specifically for use with the slit lamp, with powers up to and including 130 Diopters. Clinical experience with these lenses by investigators led to the choice of the 90 Diopter lens as the most practical for indirect ophthalmoscopy with the slit lamp. While all the lenses tested had merit, the Volk 60D and 90D lenses were commercialized providing a variety of characteristics; magnification, field of view and undilated pupil examination.
Note there had also been concurrent developmental work beginning with El Bayadi on the use of high powered lenses with the slit lamp. Unfortunately, that technique did not gain favor because of the spherical lens design and the inherent aberrations it presented. It was only with the development of the double aspheric design by Volk that the slit lamp biomicroscope became clinically feasible and worthwhile.
As the 20D, 60D and 90D lenses became industry standards, work was underway to develop additional lens options. The 78D was introduced to supplement the existing slit lamp lenses providing a higher magnification with a wider field than the 90D.
The superior quality of the Volk double aspheric design found its way into therapeutic applications. The introduction of the QuadrAspheric lens in 1990 provided a substantial leap of image quality over other lens types. The 3 mirror lens was largely used at the time for PRP, but did not have the wide field view an indirect lens could present. The new QuadrAspheric provided a complete retinal image allowing the clinician to clearly distinguish between areas to be treated or avoided. Other indirect lenses at the time did not provide such a wide field of view.
In 1989, the ‘2nd generation’ diagnostic lenses were developed, including the Pan Retinal® 2.2 for the indirect ophthalmoscope.
In 1992, things were happening at the slit lamp, with the ‘Super Series’ lenses introduction. Using high grades of glass, the lenses provided higher resolution image quality when compared to the classic 60D, 78D and 90D lenses. The Super Series also saw the introduction of much higher Diopter power lenses, providing additional utility for undilated pupil examinations.
1999 saw the 25th anniversary of Volk. From humble beginnings, the company had developed the finest optics now being used in all areas of examination, therapy and surgery, yet continued to research ways to improve and innovate.
The early part of the 21st century saw the introduction of the first of the ‘3rd generation’ Digital Series family – the Digital 1.0x. With further improvements to the double aspheric design and lens coatings, we achieved an even higher resolution image quality with improved stereopsis. The family also included the Digital Wide Field® and Digital High Mag® for the slit lamp. For BIO exams, the Digital ClearField and Digital ClearMag.
Why call them Digital Series? As these lenses were developed, we found the enhanced double aspheric design coupled with gains in the quality of our A/R coating provided a noticeable reduction in glare and reflections. This led us to realize that this helped improve photographic imaging. Photography however, is not their sole purpose. The Digital Series lenses provide the finest views for all examinations and imaging.
This spirit of innovation and improvement is a vital characteristic to our success. Take also the H-R Wide Field lens, the new standard for pan retinal diagnosis and PRP treatment. While lens technologies existed for this procedure, we found a way to design and improve the image quality further. So we did it.
While lenses are our strength, we have begun diversifying to bring to bear our design excellence for a surgical system. Our recently launched Merlin® Surgical Viewing system is the latest non-contact surgical imaging system, providing superior imaging of the eye during vitreoretinal procedures.
Another new innovation from Volk brings portability to ophthalmic imaging. Pictor is a lightweight, handheld camera that can image the retina (non-mydriatic) and external ocular structures.
We will continue to improve our current product quality and research new ways to help in the examination and treatment of the eye. Long may the ethics Dr. Volk instilled in the company continue in our spirit of improvement and long may our heritage help build our future.