A New Design for Crisp, Clear, Consistent Vision
Clinical insights from Joe Barr, OD, MS, FAAO, Bausch + Lomb
Designing a contact lens to meet the needs of astigmatic patients presents a challenge to the best lens designers. To meet this challenge, the vision scientists at Bausch + Lomb started with a blank slate. There were no ideas too farfetched, too small or too insignificant - no barriers to success. What came out of this process was our latest toric lens design - PureVision®2 For Astigmatism.
PureVision2 For Astigmatism is the only silicone hydrogel toric lens designed with aspheric optics in all meridians to reduce the positive spherical aberration that is naturally occurring in the human eye as well as what is naturally induced by spherical lens designs due to their spherical surfaces. Incorporating aspheric optics across the entire power range provides patients with clear, crisp vision all day, even in low light.
In addition to the improved optics, several experiments were undertaken to understand eyelid movement, one of the main drivers of toric lens instability. In doing so, our lens designers and clinicians created an orientation and stabilization design that is unique - Auto Align Design™.
In order to improve centration, PureVision2 For Astigmatism was designed with a larger diameter. In addition, the larger diameter optimizes the thickness of the ballasting compared to PureVision Toric (Figure 1). This helps create a more comfortable wearing experience, maintain the same large optic zone as PureVision Toric, and support the Auto Align Design.
FIGURE 1. Thickness profi les of PureVision Toric (A) and PureVision2 For Astigmatism (B), where the red color indicates the thickest portions of the lens and the blue color represents the thinnest portions of the lens.
Both lenses have two key features: a thin rounded lens design that enables a smooth, gentle transition of the lid from the lens to the conjunctiva to provide a natural feel throughout the day and a moisture-rich packaging solution to provide excellent comfort upon insertion.
When fitting patients with toric contact lenses, it's important to consider all aspects of successful contact lens wear: vision, comfort, and health. Patients are looking for contact lenses that offer crisp, consistently clear vision throughout the day without compromising comfort. As Dr. David Geffen, OD, FAAO, says, “They want that crisper vision for their active lifestyles, and it gets them excited about referring patients to me.”
Joe Barr, OD, MS, FAAO Vice President Global Clinical & Medical Affairs and Professional Services Vision Care Bausch + Lomb