What is EDGE lift contact lenses?

General definition in lens geometry: The distance between an extension of the BCOR (back central optic radius) and the absolute edge of the lens; when measured parallel to the optical axis, axial edge lift (AEL); when measured along the radius, radial edge lift (REL).

What is EDGE lift in RGP?

Edge clearance refers to the gap between the front surface of the cornea and the back surface of the peripheral curves, and it is edge clearance that is observable with fluorescein. Edge lift is a geometrical characteristic of the lens itself, and is deﬁnable in either axial or radial forms.

What is axial edge lift?

Axial edge lift (AEL) is the distance between the apex of the lens edge and the continuation of the base curve, measured parallel to the lens axis. Edge clearance, the distance between the peripheral curve’s highest point (the lens edge apex) and the peripheral cornea, can also be measured axially or radially.

How do toric contact lenses work?

The special shape of a toric lens creates different refractive, or focusing, powers that can help correct either a corneal or a lenticular astigmatism. Toric contacts have a thicker zone that keeps them from rotating when they’re in your eyes. If your lenses don’t fit well, they’ll do little to improve your vision.

What is 3 point touch contact lens?

The three-point touch fitting method allows the contact lens to bear lightly on the apex of the cornea, with heavier bearing on the paracentral cornea. This technique is associated with good visual acuity.

How do I know my contact lense power?

You’ll find that the cylinder number on a contact lens prescription is always a minus number. This indicates the extra power you need for astigmatism correction. A higher number denotes a more severe level of astigmatism. The cylinder value for a glasses prescription on the other hand can be a plus or minus.

How do you fit RGP for keratoconus?

With this technique, you first fit the patient with a large diameter soft lens with proper centration and movement. Next, take keratometry or topography readings of the “new” corneal surface and fit an RGP on top of the soft lens. Both materials should be highly oxygen permeable.

What is axaxial edge lift?

Axial edge lift (AEL) is the distance between the apex of the lens edge and the continuation of the base curve, measured parallel to the lens axis.

What is radial edge lift in CNC?

Most computerized numerical controlled (CNC) lathing calculations are performed in terms of axial edge lift. So, if you provide a radial edge lift measurement to a lab that interprets it as an axial measurement, the contact lens you receive will differ from what you had intended.

What is edge lift of a lens?

Can silicone hydrogel lenses be fitted with an edge lift?

Often the lens will ride on the lower lid margin causing varying degrees of discomfort. Edge lift does not reduce or settle with silicone hydrogel lenses and the patient should not be fitted with lenses with this appearance. If possible a steeper basecurve should be trial fitted and assessed.