Question

what is a bio focal length ?​

Answer 1

Answer:

The longer the focal length, the narrower the angle of view and the higher the magnification. The shorter the focal length, the wider the angle of view and the lower the magnification.

Answer 2

Answer:

$\huge \red{\mid{\underline{\overline{\textbf{Answer\:᭄}}}\mid}}$

Bifocal lenses have two prescriptions in the same lens. Having one section that corrects for distant vision and another that corrects for near vision, as an eyeglass lens.