What are Refractive Errors?
In refractive errors, the shape of the eye prevents light from focusing on the retina. The length of the eyeball (longer or shorter), changes in the shape of the cornea, or aging of the lens can cause refractive errors. There are different types of refractive errors, but the most common are Myopia, Hyperopia, and Astigmatism and Presbyopia.
Refraction is the bending of light as it passes through one object to another. Vision occurs when light rays are bent (refracted) as they pass through the cornea and the lens. The light is then focused on the retina. The retina converts the light-rays into messages that are sent through the optic nerve to the brain. The brain interprets these messages into the images we see.
Myopia, presbyopia and astigmatism can be corrected with eyeglasses, contact lenses, or surgery. The simplest means of correcting presbyopia is eyeglasses. Eyeglasses for presbyopia have higher focusing power in the lower portion of the lens. This allows you to read through the lower portion of the lens and see properly at distant through the upper portion of the lens. It is also possible to purchase reading eyeglasses. These types of glasses do not require a prescription and can help with reading vision.