The Normal Eye
The Myopic Eye
The nearsighted eye (myopia) is somewhat longer than the normal eye. This causes the light rays to focus at a point in front of the retina, resulting in a blurry view of distant objects.
The Hyperopic Eye
The farsighted eye (hyperopia) is shorter than normal. Light rays are aimed at a focus point behind the retina causing blurring of objects viewed up close.
Other common vision problems include astigmatism and presbyopia. With astigmatism the curvature of the cornea is uneven, causing a distortion of images. This distortion is especially noticeable after dark and with bright lights. With astigmatism, objects at all distances appear blurred.Presbyopia is caused by a loss of focusing flexibility in the eye and affects everyone, often starting in the mid-forties . This makes it difficult to view objects up close while wearing corrective eyewear for nearsightedness. People with this condition often wear reading glasses and bifocals (glasses that focus different ways for up close and distance viewing). Alternatively, if they are nearsighted, they may read by removing their eyeglasses and using their nearsightedness to read.