The contact and intraocular lens industries will benefit from U.S. patent number 9,019,485 awarded to Lumetrics (Rochester, NY) for a simplified apparatus that measures the optical performance characteristics and dimensions of an optical element using a single system. Prior to its introduction, customers would have needed three separate optical systems to make these measurements.
Typically, contact lenses and other lens products are measured for power and spherical aberrations via a Shack-Hartmann wavefront sensor (SHWFS). Center thickness measurements are then made with an optical comparator or touch gauge. Finally, a vision system is needed to determine outside diameter. The Lumetrics system, which includes a low-coherence interferometer (LCI), uses one instrument to measure center thickness (CT), sagittal height (SAG), base power, cylinder power, cylinder axis, wavefront aberrations including spherical aberration and other Zernike polynomial aberrations, base radius of curvature, index of refraction, and outside diameter, and can read alphanumeric features and alignment marks. In addition, the distance from the back of the lens relative to the object plane can be measured, enabling the operator to achieve the most accurate power measurements in the ophthalmic industry, according to Lumetrics. Beyond saving floor space and equipment costs, product handling is also minimized. Lumetrics intends to have a commercially available product in late 2015.
Contact Steve Heveron-Smith at [email protected].
