What is the condition characterized by difficulty seeing nearby objects and is treated with a convex lens?

The condition characterized by difficulty seeing nearby objects and treated with a convex lens is hyperopia, often referred to as farsightedness. In hyperopia, distant objects may be seen clearly, but close objects appear blurry. This occurs because the eye is either too short or the cornea has too little curvature, which causes light entering the eye to focus behind the retina rather than directly on it. Convex lenses are used in glasses for hyperopia to converge light rays before they enter the eye, ensuring that they focus correctly on the retina and allowing for clear vision of nearby objects.

Understanding hyperopia is crucial, as it commonly presents in both children and adults, and the need for vision correction can affect daily activities such as reading or using digital devices. The other conditions, while related to vision, involve different mechanisms such as myopia (nearsightedness), where nearby objects are seen clearly but distant ones are not, astigmatism, which is due to an irregular shape of the cornea or lens, leading to distorted vision, and presbyopia, a condition related to aging where the eye's ability to focus on close objects decreases over time.