초록

A contact lens is disclosed having a front surface and a back surface. The lens contains a continuously varying aspheric surface on one or more of these surfaces.

대표청구항 ▼

1. A contact lens comprising:a front surface and a back surface, one of the front surface and the back surface being an aspheric surface having an equatorial angle φ wherein an eccentricity of the aspheric surface varies continuously as a function only of the angle φ,wherein the eccentri

1. A contact lens comprising:a front surface and a back surface, one of the front surface and the back surface being an aspheric surface having an equatorial angle φ wherein an eccentricity of the aspheric surface varies continuously as a function only of the angle φ,wherein the eccentricity varies according to the following equation: e (φ)= A−B sin(φ)for φ=0° to 360°wherein the constants A and B are defined by A= ( e max +e min )/2 B= ( e max −e min )/2 e max =e (270°)= A+B e min =e (90°)= A−B. 2. The contact lens of claim 1 wherein the aspheric surface is the front surface. 3. The contact lens of claim 2 wherein the aspheric surface is the back surface. 4. A contact lens comprising:a top portion and a bottom portion having an equatorial angle φ, the top portion having a constant eccentricity as a function of the angle φ, the bottom portion having an eccentricity that varies continuously as a function only of the angle φ. 5. The contact lens of claim 4 wherein the top portion has an eccentricity to provide a distance correction power and the bottom portion has an eccentricity to provide, in part, a near correction power. 6. The contact lens of claim 5 wherein the near correction power has a maximum correction power where the angle φ is in the range 225°-315°. 7. The contact lens of claim 6 wherein the near correction power has a maximum correction power where the angle φ is 270°. 8. The contact lens of claim 7 wherein the eccentricity of the bottom portion varies by the function: e (φ)= A−B sin(φ)for φ=180° to 360°wherein the constants A and B are defined by min max −e min e max =e (270°)= A+B e min =e (90°)= A. 9. The contact lens of claim 8 wherein the top portion and the bottom portion are on a back surface. 10. The contact lens of claim 8 wherein the top portion and the bottom portion are on a front surface. 11. The contact lens of claim 8 wherein the lens includes a ballast. 12. A contact lens comprising:a top portion and a bottom portion, and two opposite side portions, the top portion having a first eccentricity along a selected arc, the bottom portion having a second eccentricity different from the first eccentricity a long the selected arc and the side portions having an equatorial angle φ and an eccentricity that that varies continuously as a function of the angle φ along the selected arc. 13. The contact lens of claim 12 wherein the top portion has an eccentricity that provides a distance correction power and the bottom portion has an eccentricity that provides a near correction power. 14. The contact lens of claim 13 wherein the first side portion is found at φ=150° to 210° and the second side portion is found at φ=330° to 360° and 0° to 30°. 15. The contact lens of claim 14 wherein the eccentricity of the side portion varies according to the following equations: e (φ)= e max −( e max −e min )(φ+30°)/60°for φ=0° to 30° e (φ)= e max +( e max −e min )(φ−150°)/60°for φ=150° to 210° e (φ)= e max −( e max −e min )(φ−330°)/60°for φ=330° to 360°. 16. The contact lens of claim 15 wherein the top portion and the bottom portion are on a front surface. 17. The contact lens of claim 16 wherein the lens includes a prism ballast. 18. A contact lens comprising:a front surface and a back surface, one of the front surface and the back surface being an aspheric surface having an equatorial angle φ wherein an eccentricity of the aspheric surface varies continuously as a function of the angle φ, wherein a near correction power is located between 30°-150& #xb0; and a distance correction power is located between 210°-330°.