LEARN MORE ABOUT YOUR EYES
("normal" or "perfect" vision) is the condition in which the image of a faraway object is focused exactly on the retina, resulting in clear distant vision.
Myopia (nearsight) is the condition in which the image of a faraway object is focused in front the retina because the eyeball is too long or the refractive power of the eye is too strong. This results in the far vision being blurry. When a near object is viewed, it is focused on the retina, resulting in the near sight being clear.
Hyperopia (farsight) is the condition in which the image of a faraway object is focused behind the retina, either because the eyeball is too short, or because the refractive power of the eye is too weak. When a near object is viewed, the image becomes focused even further behind the retina, resulting in the far sight being clearer than the near sight. This may cause headaches, eyestrain, and/or fatigue.
Astigmatism is the condition in which the images of both faraway AND near objects become split into two, making the vision blurry at ALL distances. Astigmatism may cause eye strain and may occur with nearsightedness or farsightedness. Symptoms include headache, eye strain, fatigue, and fluctuating vision.