Eye Doctors Glossary of Terms

in Bloomington and Peoria, Illinois

Astigmatism - A vision problem that results in blurred distance and/or near vision. Light rays entering the eye are bent unequally, which prevents the formation of a sharp point of focus on the retina. This creates a blurring of parts of objects you see.

Cornea - The clear front surface of the eye. Refractive surgeries like PRK, LASIK and RK reshape this surface to correct vision problems.

Diopters - A unit of measurement for myopia, hyperopia and astigmatism that usually falls within a scale of +14 to -14. A positive number indicates hyperopia and a negative number indicates myopia. Positive and negative numbers are also used to indicate astigmatism. Whether the number is positive or negative, the higher the number the greater the extent of the vision problem.

Farsightedness - A common term for hyperopia, a vision problem that most commonly results in blurred close vision. Moderate to severe hyperopia may also result in blurred distance vision. The cornea and lens focus light rays behind, rather than directly on, the retina.

Hyperopia - A vision problem that most commonly results in blurred close vision although moderate to severe hyperopia may also result in blurred distance vision. The cornea and lens focus light rays behind, rather than directly on, the retina.

Lens - A structure inside the eye that helps to focus light on to the back of the eye.

Lower Order Aberrations - A collective term for a series of common vision problems including myopia, hyperopia and astigmatism.

Myopia - Another term for nearsightedness. A condition of the eye that results in blurred distance vision. The cornea and lens focus light rays from distant objects in front of the retina. This incorrect focusing of light results in blurred images of objects at a distance.

Nearsightedness - A common term for myopia. A condition of the eye that results in blurred distance vision. The cornea and lens focus light rays from distant objects in front of the retina. This incorrect focusing of light results in blurred images of objects at a distance.

Ophthalmologist - A medical doctor who specializes in the eye and is licensed to perform surgery on the eye. All LASIK surgeons are ophthalmologists.

Optometrist - An eye care specialist who specializes in the examination, diagnosis, treatment, management and prevention of diseases and disorders of the eye and associated structures.

Presbyopia - A condition commonly due to aging, is due to a stiffening of the lenses, which results in an eye that can no longer accommodate for near or "reading" vision. The individual is no longer able to read clearly and requires reading glasses.

Refractive Errors - Vision problems caused by an imperfect optical system, most commonly myopia, hyperopia and astigmatism.

Retina - The light sensitive nerve layer in the back of the eye that receives visual stimuli that are transmitted to the brain.

Visual Acuity - Another phrase for visual clarity, a measure of the eye`s ability to distinguish the shape of objects. Visual acuity is measured with a traditional eye chart, with the goal traditionally being 20/20.

Wavefront Mapping - A sophisticated way to represent visual disorders, these maps are created by passing a narrow ray of eye-safe light through the optical system and measuring the optical distortions as the light exits the eye. With the LADARVision® system, the resulting wavefront maps are used to provide fully customized vision correction, to address both lower- and higher-order aberrations, through the CUSTOMCORNEA® procedure.