Final answer:
The industry standard for straight top bifocals is the Flat-top Bifocal.
Step-by-step explanation:
In the field of Optometry, the industry standard for straight top bifocals is the Flat-top Bifocal. This type of bifocal lens has a distinct line separating the distance prescription at the top and the near prescription at the bottom. It is commonly used to correct both distance vision and presbyopia, the age-related loss of near vision.
The flat-top bifocal is widely used because it offers a clear separation between the two prescriptions, making it easier for the wearer to transition between tasks that require different levels of visual acuity.