The correct option for the type of lens used to correct hyperopia (farsightedness) is **B. Convex lens**. ### Detailed Explanation **Understanding Hyperopia:** - Hyperopia, or farsightedness, is a common vision condition where distant objects can be seen clearly, but close objects appear blurry. This occurs because the light entering the eye is focused behind the retina rather than directly on it. This misalignment can be due to the eyeball being too short or the cornea having too little curvature. **Role of Lenses:** - Lenses are used to correct vision by altering the path of light rays entering the eye. The goal is to ensure that light rays converge at the correct point on the retina. **Convex Lens:** - A convex lens is thicker in the middle than at the edges and is known for its ability to converge (bring together) light rays. When a convex lens is placed in front of a hyperopic eye, it helps to bend the incoming light rays inward, allowing them to converge before they reach the eye. This adjustment ensures that the light focuses directly on the retina, improving the clarity of close-up vision. **Why Option B is Correct:** - The convex lens effectively compensates for the eye's inability to focus light correctly, making it the appropriate choice for correcting hyperopia. ### Why the Other Options are Incorrect: **A. Concave lens:** - A concave lens is thinner in the middle and thicker at the edges. It diverges light rays, causing them to spread out. This type of lens is used to correct myopia (nearsightedness), not hyperopia. Therefore, it does not help in focusing light on the retina for someone with hyperopia. **C. Bifocal lens:** - Bifocal lenses contain two different optical powers: one for distance vision and another for near vision. While they can be useful for individuals who have both hyperopia and presbyopia (age-related difficulty in seeing close objects), they are not specifically designed to correct hyperopia alone. Thus, they are not the primary choice for correcting hyperopia. **D. Cylindrical lens:** - Cylindrical lenses are used to correct astigmatism, which is caused by an irregular shape of the cornea or lens. They focus light differently in one direction than in another. While they can be part of a prescription for someone with hyperopia and astigmatism, they do not directly correct hyperopia by converging light rays. ### Summary of Key Points: - Hyperopia (farsightedness) occurs when light focuses behind the retina. - A **convex lens** converges light rays, allowing them to focus on the retina, correcting hyperopia. - **Concave lenses** diverge light and are used for myopia, not hyperopia. - **Bifocal lenses** are for individuals needing correction for both distance and near vision, not specifically for hyperopia. - **Cylindrical lenses** correct astigmatism and do not directly address hyperopia. This understanding of lenses and their functions is crucial for anyone studying optics in physics or preparing for exams related to vision correction.