High Add Progressive Bifocals
Normally lens manufactures only create progressive bifocal up to +3.50D or +4.00D in power. Today with new fabrication equipment, it is possible to create an invisible progressive bifocal up to +8.00. Thus the patient can get up to 2X magnification in the full near power, but still have the ability to focus across a range of distances. This is accomplished by using new computerized surfacing equipment to create a second invisible bifocal that is ground on the back of an existing progressive. Thus a +3.00D PAL could also have an addition +3.00D on the back to give a total of +6.00D bifocal.
This technology helps people with a mild to moderate loss have extra power to read small print and an intermediate range to help them with other tasks.