Farsightedness, or hypermetropia, is when people can see far away but not up close. Hyperopia means that the eye is underpowered. The rays of light coming from an object at close range will come to focus at a point behind the retina, therefore causing a blurry image to form. This image can be brought into focus by placing plus power or a convex lens in front of the eye, such as reading glasses.
Nearsightedness, or myopia, is when people can see well close up but blurry at a distance. There are more than 70 million people in North America that are nearsighted. In myopic vision, light rays coming from a distant object will come to focus just in front of the retina. The eye has too much plus power, thus causing a blurred distant image. The more myopic you are, the more blurred objects will appear in the distance. The eye will need a minus power or concave lens to correct that problem.
Astigmatism is a condition in which light rays are not refracted equally in all directions so that a point focus is not attained. The eye has a more oval shape, like a football. People with astigmatism experience a distortion or tilting of images. This is due to the unequal bending of light coming into the eye.
Presbyopia is a condition where the crystalline lens loses elasticity and is no longer able to focus images close up. This diminished power of accommodation occurs with aging and normally starts at around the age of 40 and significantly by 45.
Glaucoma refers to a group of diseases that increase interocular pressure, resulting in damage to the optic nerve and retinal nerve fibers. This is a common cause of preventable vision loss.
Cataract is a cloudiness or opacity of the crystalline lens that may prevent a clear image from forming on the retina. This lens may require surgical removal if visual loss becomes significant. Cataracts can be congenital or caused by trauma, disease or age.
Age-related macular degeneration is the leading cause of permanent blindness in the elderly. There are two types: dry (non-exudative), which means the changes are slow and involve the growth of drusen (yellowish round spots); and wet (exudative), which is when fluid or blood leak into the membrane. This can cause epithelial detachment and possibly a detached retina. Careful monitoring is strongly recommended.
If your vision has become blurred or you’re experiencing other vision-related conditions, please contact us.