Example 4

FIG. 8 illustrates an exemplary embodiment of the power profile of an optic zone for a lens. The example of FIG. 8 is directed to an ophthalmic lens comprising:

an optic zone comprising:

a primary area 301 having a primary optical power;

a central portion 311;

a first secondary area 302 within the central portion 311 having a first secondary optical power;

a first power transition area 304 having a first power transition from the primary area 301 to the first secondary area 302;

a peripheral portion 310;

a second secondary area 303 within the peripheral portion 310 having a second secondary optical power; and

a second power transition area 305 having a second power transition from the primary area 301 to the second secondary area 303;

wherein the primary optical power is selected according to a prescription for refractive correction, the first secondary optical power is more positive than the primary optical power and the second secondary optical power is more positive than the primary optical power;
wherein the first power transition comprises: at least a first step 306 in the first power transition area 304 in which the rate of change in power, from the first secondary optical power in the first secondary area 302 to the primary optical power in the primary area 301, changes at a first junction 313 between a first transition region 312 within the first power transition 304 and the first step 306 followed by a change in the rate of change in power at a second junction 314 between a second transition region 315 within the first power transition 304 and the first step 306, and
at least a second step 307 and a third step 308,
wherein the second step 307 lies within the second power transition area 305 in which the rate of change in power, from the second secondary optical power in the second secondary area 303 to the primary optical power in the primary area 301, changes at a third junction 318 between a third transition region 319 within the second power transition 305 and the second step 307 followed by a change in the rate of change in power at a fourth junction 317 between a fourth transition region 316 within the second power transition 305 and the second step 307, and the third step 308 lies within the second power transition area 305 in which the rate of change in power, from the second secondary optical power in the second secondary area 303 to the primary optical power in the primary area 301, changes at a fifth junction 321 between a fifth transition region 321 within the second power transition 305 and the third step 308 followed by a change in the rate of change in power at a sixth junction 320 between the third transition region 319 within the second power transition 305 and the third step 308.

In the exemplary embodiment of FIG. 8, the power of the primary area 301 is approximately −2 D and has a progression in optical power progressively increasing in positive power towards the periphery. Such peripheral progressive increase in power may result in effective or improved visual performance or vision performance in one or more aspects of visual performance or vision performance. For example, spherical aberration may be included in the primary area to correct, reduce or manipulate aberration of the eye and ophthalmic lens combined. Such an exemplary inclusion of spherical aberration may improve clarity of vision, contrast, contrast sensitivity, visual acuity, and overall quality of vision or combinations thereof.

In certain embodiments, the power of a primary area may be constant, substantially constant, progressively increasing, progressively decreasing, modulated (i.e. undulating along its power profile), possess an aberration profile (e.g. spherical aberration) or combinations thereof.

In the exemplary embodiment of FIG. 8, the powers of the first step 306, second step 307 and third step 308 are not constant within the steps.

In certain embodiments, the power profile within a step may be constant, or substantially constant, or progressively changing. In certain embodiments in which the power of a step is progressively changing, the change in power across the width of the step may be between 0 and 0.2 D, 0 and 0.15 D or 0 and 0.1 D. In certain embodiments in which two or more steps have progressively changing power profiles, the rate of change of the power profiles between the two or more steps may be equal or unequal.

In the exemplary embodiment of FIG. 8, the power profile along the first power transition 304 and the second power transition 305 are monotonic.

Monotonic means that where a power transition decreases from one area to another area (for example, between a first secondary area and a primary area), the power profile is either decreasing or constant or substantially decreasing or substantially constant along the power transition including steps within the power transition. Conversely, where a power transition increases from one area to another area (for example, from a primary area to a second secondary area), monotonic means the power profile is either increasing or constant or substantially increasing or substantially constant along the power transition including steps within the power transition. In certain embodiments, a power transition will have a monotonic power profile.

In the exemplary embodiment of FIG. 8, changes in the rate of change in optical power at junctions 313 and 314 that forms the first step 306 and changes in the rate of change in optical power at junctions 317 and 318 that forms the second step 307 are less rapid and/or more gradual.

In certain embodiments, a change in the rate of change in optical powers may be considered “gradual” when the change in rate of change occurs over a junction width of between 0.15 and 1 mm, 0.25 and 0.75 mm or 0.3 and 0.5 mm.

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