Final answer:
Option B. B&L Soflens Multifocal lenses use a design with gradual transitions from distance to near vision, while PureVision Multifocal lenses have a center-near design for simultaneous vision. Myopia is corrected with diverging lenses, hyperopia with converging lenses, and presbyopia is also corrected with converging lenses to add close vision power.
Step-by-step explanation:
B&L Soflens Multifocal and PureVision Multifocal contact lenses are designed to correct presbyopia, a condition commonly associated with the loss of the eye's ability to focus on close objects due to age. The design B) Gradual transition from distance to near vision applies to the Soflens Multifocal, which uses concentric rings with different powers. This design allows for a smooth transition between different lens powers as the eye moves from looking at distant objects to closer ones.
On the other hand, PureVision Multifocal lenses employ a D) Center-near design for simultaneous vision, where the central portion of the lens focuses on near vision while the peripheral part is for distance vision. The lenses enable simultaneous vision through multiple zones of focus that the brain learns to select based on the object being viewed.
In terms of vision correction, nearsightedness (myopia) is addressed with the use of a diverging lens to spread the rays slightly and reduce lens power so that they focus onto the retina correctly. Farsightedness (hyperopia) is corrected with a converging lens, which gathers the rays slightly so they focus onto the retina. For presbyopia, a converging lens is utilized to add power for close vision.