Question

how do glasses work?

Answer 1

Hint : The retina, located in the back of the eye, is the layer of cells that reacts to light. This reaction travels to the brain, which translates the activities of the cells into an image. When you focus your eyes on something, the light rays come together inside your eye. For individuals with perfect vision, the rays will focus on the part of your retina that produces a clear image. The pupil and cornea shrink and focus the image, so if your pupils or cornea have an irregularity, your vision will be blurry. If you have nearsightedness or farsightedness, it means your eyes have difficulty focusing light on the spot of your retina that produces the clearest image. Glasses correct vision by allowing your eyes to focus light on the correct spot of your retina.

Complete step by step explanation:
Step 1: In cases of nearsightedness and farsightedness, images you see don’t focus on the right spot of the retina. With nearsightedness, the image focuses in the front of the retina, and with farsightedness, the image focuses behind the retina. Individuals with astigmatism have an irregularly shaped cornea, which means it bends light in different directions. In simple words, the glasses correct the vision problem. Let us analyze each vision problem, namely nearsightedness, farsightedness, and astigmatism.
Step 2: Nearsightedness occurs because the image comes into focus before it reaches the retina. In this vision problem, closer objects are in focus but the distant objects are out of focus. We use the concave lens to solve this problem. Because the concave lens spreads the light away from the center of the lens and moves the focal point up. The stronger the lens, the farther the focal point is from the lens.
Step 3: Hyperopia which is also called farsightedness occurs because the image doesn't come into focus before it gets to the retina. Close objects are out of focus, distant objects are in focus. To cure this problem we use a convex lens. Because a convex lens bends the light towards the bottom and top of the lens, pushing the local point back to the retina. The stronger the lens, the closer the focal point is to the lens.
Step 4: In Astigmatism the shape of the lens or cornea is distorted so light makes two focal points instead of one. More curvature in one direction than in the other results in blurred vision at all distances. Lenses can be cut to bring the image closer, further away, or correct other vision problems like double vision.

Note: To understand how glasses work, we should be familiar with how the eyes focus light. The pupil allows light into the back of the eye. The cornea is the top layer of the eye where all light must pass through. The lens works with the cornea to fine-tune vision. The retina is a complex layer of cells that react to light. Scattered light merges together and is focused on the retina. Images must shrink and curve to match the shape of the retina. Reaction to light is relayed from the retina to the brain and is translated into an image.