In the rich fabric of nature's creation, the eyes of some insects and animals stand out as amazing instances of optical prowess. These compound eyes, which are made up of a slew of small individual lenses [1], allow these critters to observe the world as a mosaic of various pictures, with each lens catching a unique perspective. Considering the compound eyes of a dragonfly, which are made up of hundreds of tiny lenses, shows the amazing potential of compound optics in the natural world and enables the dragonfly to follow prey with startling precision. This mesmerizing phenomena has long captivated scientists and engineers alike, driving them to discover the mysteries of nature's optical marvels.

As a counterpoint to these natural beauties, a groundbreaking technology known as “metalens" arises in the world of human invention. Lin et al. [2] originally suggested a particular type of silicon nanorod-based dielectric gradient metasurface in 2014. The Pancharatnam-Berry phase theory [3,4] and propagation phase theory [[5], [6], [7]] was used to implement the necessary phase profiles for axicons and lenses. They are meticulously built from numerous small unit cells, each of which contributes to the shape and intensity of light, much like the compound eyes of dragonflies and other insects. Metalenses have the unique capacity to precisely modify and regulate the characteristics of light such as phase, amplitude, and polarization at will due to their unit cells, which are organised in a certain pattern using a compact, simple-to-make technology [6,8] [[6], [8], [9], [10], [11]] [[6], [8], [9], [10], [11]]. Metalenses can demonstrate these excellent qualities and utility in many different applications, including nonlinear dynamics [12], light beam shaping [[13], [14], [15], [16]], highly dimensional holographic pictures [[17], [18], [19], [20]], polarization control and analysis [[21], [22], [23]], invisibility cloak carpet [24], etc. Latest advancements highlight novel applications of symmetry transformations in quadratic phase metasurfaces enabling planar metalenses to realise large fields-of-view comparable to conventional rotational symmetry lenses [[25], [26], [27]] [[25], [26], [27]] [[25], [26], [27]]. They have several potential uses in fields including medical, virtual reality, augmented reality, and others. However, a high aspect ratio is still a drawback which leads to potential structural weaknesses and less responsive handling. Balancing these factors is crucial for better performance of the designed metalens.

The amazing fusion of biological inspiration and human invention is revealed as we explore further into the realm of metalenses. Here in this paper we demonstrate a metalens with human eye mimetic meta-atom. For the first time a metalens is designed with highly reduced and constant aspect ratio giving it higher mechanical stability, ease of integration and also resistance to environmental factors. The designed meta-atom is made up of two concentric cylinders with outer cylinder made of amorphous Si. For comparison we have varied the material of inner core as GaN, GaP and SiO2 and studied their transmission and phase profile characteristics. Compared with previously reported metalenses, the human eye mimetic metalens shows better focusing efficiency of 52% with highly reduced aspect ratio of as low as 1.4 for a high numerical aperture of 0.4. The designed metalens also eliminates the chromatic aberration for a continuous range of 1300 nm–1500 nm.