Volasfeer / Ellipticon
Correcting contact lens
The elliptical contact lens for eccentricity values higher than 0.45
In case of a standard elliptical contact lenses that are dimensional stable, there is a limitation to the available eccentricity and makes these lenses partially usable and in many cases gives moderate results. The choice between one or two eccentricities is certainly not sufficient to obtain a correct fit. The problems, gradual closure with too little eccentricity of the contact lens and poor centering and excessive deposits with too great eccentricity, are of course known from practice. Changing the basic curve radius is not a correct solution and causes other problems. The concept, a comfortable, dimensional stable contact lens, requires that the value of the lens eccentricity is in the right proportion to the corneal eccentricity. Especially with a spherical or almost spherical cornea, an elliptical contact lens is not always used without risk; the tear flow is then too low to ensure metabolism of the cornea in the longer term.
Spherical, Multifocal Prestige, Bifocal, Toric