Varifocal optical assembly providing astigmatism compensation

A head mounted display comprising:

• a display configured to emit image light;
• and
• a varifocal optical assembly configured to provide astigmatism compensation, the varifocal optical assembly comprising:
• a first liquid crystal lens including a liquid crystal disposed between opposing substrates;
• a first electrode pattern disposed on at least one substrate, wherein the first electrode pattern includes a set of two or more parallel conductors each having a length proportional to the longest dimension of a clear aperture of the liquid crystal lens, wherein adjacent conductors of the set of two or more parallel conductors are separated by a gap and are configured to generate a voltage distribution within the liquid crystal layer that results in the liquid crystal layer exhibiting cylindrical focal power.

A method comprising:

• transmitting light through a varifocal optical assembly configured to provide astigmatism compensation comprising a of plurality of electrode patterns disposed on at least one substrate of a liquid crystal lens assembly, the plurality of electrode patterns each including a set of parallel conductors, the plurality of electrode patterns electrically isolated from each other by an insulator and rotated at an angle with respect to each other;
• determining an astigmatism correction axis;
• and
• adjusting the cylindrical focal power of the varifocal optical assembly configured to provide astigmatism compensation by changing the voltage applied to the conductors of the electrode pattern of the plurality of electrode patterns having conductors the most parallel to the astigmatism correction axis.