E-commerce is a major factor in the U.S. economy because it assists companies with many levels of current business transactions, as well as creating new online business opportunities that are global in nature.
Eye Health. A bifocal is a lens that has two focal points, usually one lens for viewing distant objects, and one lens for viewing close objects. A bifocal is also known as a multi-focal lens. Ben Franklin is credited as the inventor of the original bifocal lens. Presbyopia.
Step 3. Wear only your new bifocals. Put away your old pair of glasses if you previously wore regular lenses. Switching back and forth between glasses makes the adjustment process more difficult and may extend the length of time it takes.