Hypermetropia eyes can be corrected by using which lens (concave or convex)?
The correct answer and explanation is:
Hypermetropia, also known as farsightedness, is a common refractive error where distant objects are seen clearly, but nearby objects appear blurry. The condition occurs when the eyeball is too short relative to the focusing power of the cornea and lens, or the cornea is too flat. This causes light entering the eye to focus behind the retina instead of directly on it.
To correct hypermetropia, convex lenses (also known as plus lenses) are used. Convex lenses converge light rays before they enter the eye, which helps shift the focus point forward onto the retina. This compensates for the eye’s inability to focus on close objects.
When light passes through a convex lens, it converges, making the image appear clearer and focused directly on the retina, improving near vision. Convex lenses are prescribed based on the degree of farsightedness, with stronger lenses used for more severe cases.
The correction works because the convex lens alters the path of light entering the eye. In a hypermetropic eye, without correction, the light is focused behind the retina. The convex lens redirects the light rays so they focus directly on the retina. This adjustment restores proper focus for close-up objects, making them appear sharp and clear.
In contrast, concave lenses are used for myopia (nearsightedness), where the light focuses in front of the retina. Concave lenses diverge light rays before they enter the eye, moving the focus point backward onto the retina. Therefore, convex lenses are specifically designed for hypermetropia, aiding in the proper visual focus for near vision.