A lens that makes use of polarization modulation to alter the geometric phase of light is being studied as a promising optical element for presbyopia. The lens is formed with liquid crystals grating structures act as a converging lens for right-handed circularly polarized light and a diverging lens for left-handed circularly polarized light resulting in positive and negative defocus for unpolarized incident light. Integrating a higher focal length geometric phase lens with a shorter converging lens creates bifocality. The geometric phase ophthalmic lenses can provide improved visual outcomes without undesired cosmesis effects. We demonstrate that such lenses can be a prominent alternative to multifocal lenses for presbyopics. We evaluate its applicability using wave optics analysis with a model eye to determine its pros and cons.

一种利用偏振调制来改变光的几何相位的镜头正在被研究为老花眼的一种有前途的光学元件。该镜头由液晶光栅结构组成，这种结构可以使右旋圆偏振光聚焦，并使左旋圆偏振光发散，在入射光无偏振的情况下会产生正负离焦效果。将一个具有更高焦距的几何相位透镜与较短的会聚透镜结合可以形成双焦点。几何相位眼镜透镜可以在不产生不良外观影响的情况下提供更好的视觉效果。我们证明，这种镜头可以成为多焦点透镜治疗老花眼的一个显著替代品。我们使用模型眼睛进行波光学分析来评估其适用性，并确定其优缺点。