ADD power corrects presbyopia, which affects people in their 40s and hinders their ability to focus on near objects. This makes it hard to see arm’s length (e.g., a book or phone) and far-away objects at the same time.
Bifocals only offer near and far distance correction and have an obvious line across the lens. Typically, they’re for those who already wear bifocals and have difficulty changing to the more capable progressive lens design.
What to consider before getting bifocal glasses lenses
Unlike progressives, bifocal lenses have a visible line across the middle of the lens that divides the reading and distance portion.
Bifocals only account for reading and far distance vision. They do not provide clear vision for computer or arm's length activities.
When moving your eyes between an object in the distance and up-close objects, things may suddenly 'jump' upward as there's no transition between the two prescriptions.
The key differences between bifocal glasses and progressives is the type of vision correction they offer and the look of the actual lenses.
Bifocal glasses only provide reading and far distance vision correction. They also have a visible line on the surface of the lens that divides the two different prescriptions.
Progressives provide vision correction across near, intermediate, and far distances, allowing you to see comfortably at all ranges. They don’t have a visible line and tend to be a more popular option because you get both the convenience of a more comprehensive field of vision and a cosmetic appeal.
If you want multifocal vision correction (multiple prescriptions in one lens) without a visible line across the surface, choose progressive lenses instead of bifocals. As well as getting a more subtle and stylish multifocal solution, you'll also benefit from intermediate vision correction.
For most people, progressive lenses are better than bifocals because they provide near, intermediate, and far distance correction within a modern lens design. They also don't have a visible line across the surface of the lens, and so have a more subtle and stylish finish. Bifocals may be a better option for people who would find it extremely difficult to switch to progressives.