What is age-related macular degeneration (ARMD)?
ARMD is a condition that includes deterioration of the macula, resulting in a loss of sharp central vision. There are two types – dry and wet. This is the most common cause of decreased vision after age 50.
What is astigmatism?
This results in the inability of an eye to focus sharply (at an distance), usually resulting from a spoon-like (toric) shape of the normally spherical corneal surface. Instead of being uniformly refracted by all corneal meridians, light rays entering the eye are bent unequally, which prevents formation of a sharp focus on the retina. Slight uncorrected astigmatism may not cause symptoms, but a large amount may result in significant blurring.
What is a cataract?
A cataract causes opacity or cloudiness of the crystalline lens, which may prevent a clear image from forming on the retina. Surgical removal of the lens may be necessary if visual loss becomes significant, with lost optical power replaced by an intraocular lens.
What is farsightedness?
This is also known as”hyperopia”. It is a focusing defect created by an underpowered eye, one that has insufficient refractive power relative to its front-to-back length. Light rays from a distant object enter the eye and strike the retina before they are fully focused. Farsighted people can see clearly in the distance but only if they use more focusing effort than those who have normally powered eyes; close-up vision may be blurred because it requires even more focusing effort.
What is glaucoma?
Glaucoma is a group of diseases characterized by increased intraocular pressure resulting in damage to the optic nerve and retinal nerve fibers. It is characterized by typical visual field defects and increased size of optic cup. It is a common cause of preventable vision loss and may be treated by prescription drugs or surgery.
What is LASIK?
LASIK is the abbreviation for Laser in Situ Keratomileusis. It is a method of reshaping the cornea to change its optical power. After a flap of cornea is cut with an automated microkeratome and folded back, a computer-programmed excimer laser reshapes (sculpts) the exposed surface of corneal tissue, and the flap is replaced without suturing. LASIK corrects myopia, hyperopia, astigmatism.
What is nearsightedness?
This is also known as”myopia.” A focusing defect created by an overpowered eye, one that has too much optical power for its length. Light rays coming from a distant object are brought to a focus before reaching the retina. Nearsighted people see close-up objects clearly but distance vision is blurry.
What is an ophthalmologist?
This is a physician specializing in diagnosis and treatment of refractive, medical and surgical problems related to eye diseases and disorders.
What is presbyopia?
This is diminished power of accommodation arising from loss of elasticity of the crystalline lens and/or loss of ciliary muscle function, as occurs with aging. It usually becomes significant after age 45 and may also be caused by diseases such as hypothyroidism or procedures/glaucoma.
What is a retinal detachment?
This is a separation of the retina from the underlying pigment epithelium. It is almost always caused by a leaking retinal tear, which allows fluid to pass from the vitreous into the sub-retinal space. A detachment disrupts visual cell structure and thus markedly disturbs vision, often requiring immediate surgical repair.