A bifocal lens is used for the correction of ____. The upper part of the bifocal lens is a ____ lens and the lower part is ____.
presbyopia, diverging, converging
Presbyopia is the defect of vision due to which an old person cannot see the nearby objects clearly due to loss of power of accommodation of eye. A bifocal lens is used for the correction of presbyopia. A bifocal lens is created with two different areas of vision correction, which are divided by a distinct line that sits horizontally across the lens. The top portion of the lens is used for distant, while the bottom portion of the lens is used for closer vision. So the upper part of the bifocal lens is a diverging lens and the lower part is converging.