Making Sense of Lenses

Volk ComparisonTool

Volk Optical can take you from Classic lens set to advanced Digital lenses

Lenses are one of the most important diagnostic tools for optometry students, so it’s important to invest in lenses with broad utility, performance, and quality. Once you’ve mastered basic exam techniques using a good set of classic lenses, adding an advanced set of lenses to your arsenal can bring you even greater imaging power.

Diagnostic and therapeutic lenses each have a purpose, and though many can provide a good balance of magnification and field of view, to ensure a comprehensive exam, lenses are designed with specific results in mind. A higher magnification lens can increase imaging detail, though provides a smaller field of view. Field of view can be widened by increasing the physical size of the lens, though some may find the larger lens more difficult to maneuver.

Volk offers a wide array of both BIO and slit lamp lenses – a great selection, yes – but it can be daunting as a student to know where to start. Volk recommends students build a starter lens set that includes one BIO lens and two classic slit lamp lenses.

The 20D BIO lens offers a solid balance between field of view (46º/60º) and image magnification (3.13x). It also has Volk’s patented double aspheric design, with glass lens construction for the highest imaging quality.

On the slit lamp side, our 90D is a perennial favorite, with an ideal balance between field of view (74º/89º) and magnification (.76x). The 90D is also popular for its small-pupil viewing capability. For detailed viewing of the optic nerve head and macula, Volk’s 78D provides a wider field of view (81º/97º) and increased image magnification (.93x).

Once they’ve mastered their techniques with classic lenses, many students add our Digital Wide Field to their kit. We call this 90D-upgrade a “power lens” as its 103º/124º field of view is 40% larger than that of a classic 90D. With a .72x image magnification, it provides a high resolution pan retinal exam at the slit lamp. The Digital Wide Field provides the widest field of view of any non-contact slit lamp lens available. As newly minted doctors go out and begin to practice, the benefit of being able to see more anatomy in one glimpse becomes clear. With the Digital Wide Field, exam time can be shortened, without sacrificing a clear view into the periphery.

Still not sure which lenses to choose? The product comparison tool at makes it easy to look at the specifications of Volk lenses side by side. If you are still unsure, please call us and we would be delighted to help you understand our lenses and walk you through the selection process (440-942-6161).

Stay abreast of the latest Volk news by following us on twitter @VolkOptical, liking Volk Optical on Facebook, and visiting our blog: