The GOV® series of lenses consists of multiple gas permeable lens designs and are often prescribed for more complex cases.
The modern ortho-k lens is 4 zones design with two midperipheral zones that are steeper than the central optical zone and called double reverse geometry lens.
The GOV® M4 lens is a double reverse geometry lens with the aspheric alignment zone, which is applied to every GOV® design for better centration, makes M4 unique among similar designs.
XMJ lens is a five-curve design with an aspheric alignment zone that is designed to enhance the peripheral inward force resulting in better centration and stabilization. This has the same target power range as M4 lens for lower myopia. The design is different from M4 lens by its XM structure for fitting zones, which is a patented design for managing high myopia. Though for the same power range, the XMJ lens molds the cornea faster and maintains effect longer for difficult cases. It’s useful for patients that sleep less.
The XM lens is a patented design (US# 6,543,897) for high myopia. The unique XM curvature groups enhance the peripheral inward pushing force, which may shape the mid-peripheral portion of the cornea to a greater extent than other designs.
GOV is prescribed with a trial set or in some cases may be empirically fit with central K’s (e-value if available), subjective refraction, and HVID. Using exam data, a calculator can be used to select the initial lens.
Multiple lens designs based on the case complexity.
Ideal for complex cases
High dK materials are available.