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.
Matter is defined as anything that occupies space and has mass. Mass is a measure of an object's inertia. It is proportional to weight: the more mass an object has, the more weight it has.However, mass is not the same as weight.Weight is a force created by the action of gravity on a substance while mass is a measure of an object's resistance to change in motion.atter is defined as anything that occupies space and has mass. Mass is a measure of an object's inertia. It is proportional to weight: the more mass an object has, the more weight it has.