Bifocal lenses are specifically designed to correct presbyopia, a condition common in older adults where the eyes lose their ability to focus on close objects. Bifocal lenses have two distinct optical powers to aid in viewing both near and distant objects. On the other hand, astigmatism, which causes blurred vision due to the irregular shape of the cornea or lens, is corrected using cylindrical lenses. These lenses are designed to compensate for the uneven curvature of the eye and provide clear vision at all distances. Concave lenses are prescribed for nearsightedness (myopia), while convex lenses are used for farsightedness (hyperopia). Each type of lens addresses specific vision problems, making it crucial to use the appropriate corrective lens for each condition to ensure optimal vision correction. The correct answer is [D] Spectacles with bifocal lenses are given for the treatment of astigmatism. This statement is false.