PRISMATIC CONTACT LENS
A class of prismatic contact lenses includes a first prism zone, having a first prism and a first optical power; and a progressive prism zone, adjacent to the first prism zone, having a progressive prism that varies from the first prism to a second prism. The prismatic contact lens can further comprise a second prism zone, adjacent to the progressive prism zone, having the second prism and a second optical power. Another class of prismatic contact lenses include a first prism zone, having a first prism and a first optical power; a second prism zone, adjacent to the first prism zone, having a second prism and a second optical power; and a sharp transition between the first prism zone and the second prism zone.
1 . A prismatic contact lens, comprising:
a first prism zone, having a first prism and a first optical power; and
a progressive prism zone, adjacent to the first prism zone, having a progressive prism that varies from the first prism to a second prism.
2 . The prismatic contact lens of claim 1 , wherein:
a prismatic power of the progressive prism varies progressively at least one of
in a radial direction, with an increasing radius, along an x-axis, along a y-axis, and along a tilted meridian, making an angle with the x-axis and the y-axis.
3 . The prismatic contact lens of claim 1 , wherein:
a refraction direction of the progressive prism varies progressively at least one of
in a radial direction, with an increasing radius, along an x-axis, along a y-axis, and along a tilted meridian, making an angle with the x-axis and the y-axis.
4 . The prismatic contact lens of claim 1 , comprising:
a second prism zone, adjacent to the progressive prism zone, having the second prism and a second optical power.
5 . The prismatic contact lens of claim 4 , wherein:
the first optical power is consistent with distance vision; and
the second optical power is consistent with near vision.
6 . The prismatic contact lens of claim 4 , wherein:
a difference between the first optical power and the second optical power is less than 0.5 D.
7 . The prismatic contact lens of claim 4 , wherein:
at least one of a prism refraction direction of the first prism, a prism refraction direction of the progressive prism, and a prism refraction direction of the second prism is tilted relative to a horizontal x-axis.
8 . The prismatic contact lens of claim 1 , wherein:
the first prism zone is a central circular region; and
the progressive prism zone includes a ring around the central circular region.
9 . The prismatic contact lens of claim 8 , comprising:
a second prism zone, including at least one of a ring and an annulus around the progressive prism zone.
10 . The prismatic contact lens of claim 1 , wherein:
the first prism zone includes an upper region of the prismatic contact lens; and
the progressive prism zone includes a lower region of the prismatic contact lens.
11 . The prismatic contact lens of claim 1 , comprising:
a second prism zone, wherein
the first prism zone includes an upper region of the prismatic contact lens;
the progressive prism zone includes a middle region of the prismatic contact lens; and
the second prism zone includes a lower region of the prismatic contact lens.
12 . The prismatic contact lens of claim 1 , wherein:
the prismatic contact lens is a multi-zone lens, including
first prism zones, including the first prism zone, having the first prism and the first optical power,
progressive prism zones, including the progressive prism zone, having a progressive prism that varies from the first prism to a second prism; and
second prism zones, having the second prism and a second optical power.
13 . The prismatic contact lens of claim 12 , wherein:
the first prism zones include a central region and first prism rings;
the progressive prism zones include progressive prism rings; and
the second prism zones include second prism rings.
14 . The prismatic contact lens of claim 12 , wherein:
the first prism zones include radial first prism zone segments;
the progressive prism zones include radial progressive prism zone segments; and
the second prism zones include radial second prism zone segments.
15 . The prismatic contact lens of claim 12 , wherein:
the first prism zones include horizontal first prism zone strips;
the progressive prism zones include horizontal progressive prism zone strips; and
the second prism zones include horizontal second prism zone strips.
16 . The prismatic contact lens of claim 1 , wherein:
the progressive prism zone is asymmetrically off-center.
17 . The prismatic contact lens of claim 1 , comprising:
at least one of a peripheral tapered edge, a ballast in a lower region of the prismatic contact lens, and an orientation mark.
18 . The prismatic contact lens of claim 1 , wherein:
at least one of the first prism zone and the progressive prism zone is toric.
19 . A prismatic contact lens, comprising:
a first prism zone, having a first prism and a first optical power; and
a second prism zone, adjacent to the first prism zone, having a second prism and a second optical power; and
a sharp transition between the first prism zone and the second prism zone.
20 . The prismatic contact lens of claim 19 , wherein:
at least one of a refraction direction of the first prism and a refraction direction of the second prism is different from horizontal.
21 . The prismatic contact lens of claim 19 , wherein:
the first optical power is consistent with distance vision; and
the second optical power is consistent with near vision.
22 . The prismatic contact lens of claim 19 , wherein:
the first prism zone is a central circular region; and
the second prism zone, including one of a ring and an annulus, around the central circular region.
23 . The prismatic contact lens of claim 22 , wherein:
a prismatic power of the first prism is approximately zero; and
a prismatic power of the second prism is non-zero.
24 . The prismatic contact lens of claim 19 , wherein:
the first prism zone includes an upper region of the prismatic contact lens; and
the second prism zone includes a lower region of the prismatic contact lens.
25 . The prismatic contact lens of claim 19 , wherein:
the prismatic contact lens is a multi-zone lens, including
first prism zones, including the first prism zone, having the first prism and the first optical power;
second prism zones, having the second prism and the second optical power; and
sharp transitions, between the first prism zones from the second prism zones.
26 . The prismatic contact lens of claim 25 , wherein:
the first prism zones include a central region and first prism rings; and
the second prism zones include second prism rings.
27 . The prismatic contact lens of claim 25 , wherein:
the first prism zones include radial first prism zone segments; and
the second prism zones include radial second prism zone segments.
28 . The prismatic contact lens of claim 25 , wherein:
the first prism zones include horizontal first prism zone strips; and
the second prism zones include horizontal second prism zone strips.
29 . The prismatic contact lens of claim 19 , wherein:
at least one of the first prism zone and the second prism zone is toric.
30 . A method of making a prismatic contact lens, the method comprising the steps of:
providing an injection mold, with a negative shape of a prismatic contact lens with a first prism zone, having a first prism and a first optical power; and a progressive prism zone, adjacent to the first prism zone, having a progressive prism that varies from the first prism to a second prism;
heating a soft contact lens material to a molten contact lens material;
injecting the molten contact lens material into the injection mold to create a molded contact lens;
cooling the molded contact lens by cooling the injection mold; and
removing the cooled, molded contact lens from the injection mold.
31 . The method of claim 30 , the providing step further comprising:
providing the injection mold with the negative shape of the prismatic contact lens having a second prism zone, adjacent to the progressive prism zone, having the second prism and a second optical power.