Multifocal contact lens

1. A multifocal contact lens, comprising:

a central contact lens area having a size, a position, and a first optical power;

an outer contact lens area having a size, a position, and a second optical power, the second optical power differing from the first optical power;

wherein the size, the position, and the optical power of the central contact lens area and the outer contact lens area are determined according to a measurement of the size of the pupil under a first light condition, a measurement of the reactivity of the pupil under a varying light condition or a varying focal demand, and a measurement of movement of the pupil under a varying light condition or a varying focal demand.

2. The contact lens of claim 1 , wherein:

the size of the pupil is less than a predetermined size value and the reactivity of the pupil is greater than a predetermined reactivity value; and

the optical power of the central area is configured to improve near vision and the optical power of the outer area is configured to improve far vision.

3. The contact lens of claim 1 , wherein:

the size of the pupil is greater than a predetermined size value and the reactivity of the pupil is less than a predetermined reactivity value; and

the optical power of the central area is configured to improve far vision and the optical power of the outer area is configured to improve near vision.

4. The contact lens claim 1 , wherein the central area is positioned away from a center of the contact lens, wherein the distance from the central area to the center is configured according to the movement of the pupil.

5. The contact lens of claim 1 , wherein the central area is spherical or diffractive.

6. The contact lens of claim 1 , wherein the central area is rotationally asymmetric.

7. The contact lens of claim 1 , wherein the contact lens is a rigid lens.

8. The contact lens of claim 1 , wherein the central area is rigid and the outer area is soft, or the central area is soft and the outer area is rigid.

9. A method for prescribing a contact lens, comprising:

measuring the size of a pupil under a first light condition;

measuring the reactivity of the pupil under a varying light condition or a varying focal demand;

measuring a movement of the pupil under a varying light conditions or a varying focal demand; and

determining a size and a position of a central contact lens area having a first optical power and a size and a position of an outer contact lens area having a second optical power according to the measurements, and the second optical power differing from the first optical power;

wherein the outer lens area substantially surrounds the central lens area.

10. The method of claim 9 , further comprising determining an optical power of the central area to improve near vision and an optical power of the outer area to improve far vision when the pupil size is less than a predetermined size value and the pupil reactivity is greater than a predetermined reactivity value.

11. The method of claim 9 , further comprising determining an optical power of the central area to improve far vision and an optical power of the outer area to improve near vision when the pupil size is greater than a predetermined size value and the pupil reactivity is less than a predetermined reactivity value.

12. The method of claim 9 , further comprising measuring the size of the pupil under a second light condition, and wherein the sizes of the central contact lens area and outer contact lens area are determined according to the size of the pupil under the first light condition and the size of the pupil under the second light condition.

13. The method of claim 9 , wherein the position of the central contact lens area is displaced from a center of the contact lens such that the pupil is substantially aligned with the central area under a first focal demand and the pupil is substantially aligned with the outer area under a second focal demand.

14. The method of claim 9 , wherein the position of the central contact lens area is displaced from a center of the contact lens such that the pupil is substantially aligned with the central area under a first light condition and the pupil is substantially aligned with the outer area under a second light condition.

15. The method of claim 9 , wherein the size of the central area is configured according to a variation in the size of the pupil between a first light condition and a second light condition.

16. The method of claim 9 , wherein the size of the central area is configured according to a variation in the size of the pupil between a first focal demand and a second focal demand.

17. The method of claim 9 , further comprising measuring a rotational or translational position of a predicate lens on an eye; and wherein the size, shape, and position of the central area is further configured according to the rotational or translational position.

18. A method of patient diagnosis, comprising:

measuring the size of a pupil under a first light condition;

measuring the reactivity of the pupil under a varying light condition or a varying focal demand;

measuring a movement of the pupil under a varying light conditions or a varying focal demand;

determining a size and a position of a central contact lens area and a size and a position of an outer contact lens area according to the measurements;

determining an optical power of the central area to improve near vision and an optical power of the outer area to improve far vision when the pupil size is less than a predetermined size value and the pupil reactivity is greater than a predetermined reactivity value;

determining an optical power of the central area to improve far vision and an optical power of the outer area to improve near vision when the pupil size is greater than a predetermined size value and the pupil reactivity is less than a predetermined reactivity value.

19. The method of claim 18 , further comprising: measuring the size of the pupil under a second light condition, and wherein the sizes of the central contact lens area and outer contact lens area are determined according to the size of the pupil under the first light condition and the size of the pupil under the second light condition.

20. The method of claim 19 , wherein the position of the central contact lens area is displaced from a center of the contact lens such that the pupil is substantially aligned with the central area under a first focal demand and the pupil is substantially aligned with the outer area under a second focal demand.

21. The contact lens of claim 1 , wherein the central area is aspherical.

22. The contact lens of claim 1 , wherein the contact lens is a soft lens.