| GLOSSARY |
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The adjustment for different distances whereby it is possible to focus an image on the retina by changing the curvature of the natural lens |
active eye-tracking mechanism |
An eye-tracking mechanism that provides real-time adjustment of laser spot location in response to involuntary eye movements during surgery. |
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Dimness of vision without a detectable organic lesion of the eye. |
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The space between the cornea and the iris that is filled with fluid. |
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Absence of the natural clear crystalline lens. |
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Refractive error due to the cornea being more steeply curved in one meridian as opposed to the other perpendicular to it. Objects near as well as far are out of focus. |
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Wasting away or diminution in the size of a cell, tissue or organ part. |
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The combined procedure of IOL implantation and LASIK surgery. |
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Inflammation of the eyelids. |
| blepharoplasty |
Surgery to enhance the appearance of the eyelids. |
| Bowman's membrane |
The thin membrane that separates the corneal epithelium from the corneal substance (stroma). |
| cataract |
Opacity of the natural crystalline lens. |
| clinic |
Geographic location of the activities of a medical practice. |
| cones and rods |
Cones are receptors in the retina responsible for sharp central vision as well as colour vision in bright light conditions. Rods are receptors in the retina responsible for detection of movement and vision under low light conditions. |
| contact lens |
A lens that fits over the cornea to alter the refractive state of the eye. |
| corneal asphericity |
The natural contour of the cornea. The corneal curvature does not describe a spherical contour (one radius of curvature) but rather an aspherical contour (an infinite number of radii). The term asphericity describes this constant change of rate of curvature, which is inherent to the natural human cornea. |
| corneal transplant |
A corneal transplant is usually indicated in conditions where the anatomical integrity of the cornea was compromised. It entails the surgical replacement of the cornea, with a donor cornea. |
| customized ablation |
A laser treatment specially designed for an individual eye |
| Descemet's layer |
The delicate membrane that separates the corneal endothelium from the corneal substance (stroma). |
| endothelium |
The single layer of cells lining the internal surface of the cornea. |
| epithelium |
The multi-layer of cells covering the front surface of the cornea. |
| fovea |
A depression in the inner retinal surface at the center of the macula responsible for sharp central vision. |
| hyperopia |
Far sightedness. Struggle to see close objects clearly. |
| keratoconus |
A degenerative disorder of the cornea, which causes it to thin and become conical in shape. |
| lamellar corneal flap |
The corneal flap created by special instrumentation which covers the area of laser treatment and provides the numerous advantages of LASIK superior to those of PRK. |
| large optical zone |
Wide area of laser treatment |
| macula |
An oval area on the central retina, which surrounds the fovea. |
| microkeratome |
The special instrument that forms the lamellar corneal flap. |
| monovision |
The use of each eye for different distances. Usually dominant eye for distance vision and non-dominant eye for near vision. |
| myopia |
Short sightedness. Struggle to see distant images clearly. |
| nomograms |
The quantified adjustment of a laser treatment to optimize the outcome thereof. |
| phakic lens implant |
The placement of an additional optical refractive element into the eye . |
| presbyopia |
Loss of accommodation ability with age. The crystalline lens loses its elasticity and it’s ability to change focus. |
| pterygium |
A triangular sheet of fibrovascular tissue, which invades the cornea. Develops in patients who live in hot, dry, dusty climates and experience excessive sun exposure. |
| quality of vision |
That component of the visual experience that affects optimal performance. |
| refractive surgery |
This type of surgery includes any surgical procedure aimed at normalizing an eye’s refractive (spectacle) error, minimizing / obviating the use of corrective eyewear. |
| strabismus |
A squint or misalignment of the visual axis of the two eyes. |
| stroma |
The middle (thickest) layer of the cornea. |
| trichiasis |
Eyelashes that grows in the wrong direction (is directed inward towards the eye instead of outward). |
| visual acuity |
A parameter by which a person’s sharpness of vision is measured. |
| visual axis |
The geometric line joining an object of interest with the macula within a patient’s eye. |
| visual field |
The size of the field of vision in the periphery while focusing on a central target.
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