Astigmatism, unlike normal vision, occurs when the cornea is shaped like a football (more curved in one direction than the other) and often occurs in combination with myopia (nearsightedness) and hyperopia (farsightedness). This causes light to focus in more than one point on the retina, resulting in blurry and distorted vision.
Hyperopia (farsightedness), unlike normal vision, occurs when the cornea is too flat in relation to the length of the eye. This causes light to focus at a point beyond the retina, resulting in blurry close vision and occasionally blurry distance vision as well. Usually this condition is undetected until later in life because the young eye is able to compensate for the hyperopia by contracting the internal lens of the eye.
Myopia (nearsightedness), unlike normal vision, occurs when the cornea is too curved or the eye is too long. This causes light to focus in front of the retina, resulting in blurry distance vision.
Myopia is a very common condition that affects nearly 30 percent of the U.S. population. It normally starts to appear between the ages of eight and 12 years old, and almost always before the age of 20. As the body grows, the condition often worsens. It typically stabilizes in adulthood.
Presbyopia is a vision condition in which the lens loses its flexibility, making it difficult to focus on close objects. During the early and middle years of life, the crystalline lens of the eye has the ability to focus both near and distant images by getting thicker for near objects and thinner for distant objects. When this ability is lost, presbyopia results.