Scleral lenses have gained popularity in the last decade. From a lens with limited viability for over 100 years to the fastest growing segment of the gas permeable lens market, scleral lenses have come a long way.
Mass and Weight. The mass of an object is a fundamental property of the object; a numerical measure of its inertia; a fundamental measure of the amount of matter in the object. Definitions of mass often seem circular because it is such a fundamental quantity that it is hard to define in terms of something else.
Definition of Mass. Mass is the quantity of matter in an object. More About Mass. Mass is often called as weight. Mass can be measured in both metric and customary units. Kilogram, gram, and milligram are the metric units whereas ounces and pounds are the customary units.