This invention is directed to a system and method to create three dimensional tomography using a Fresnel lens with broadband terahertz (THz) pulses.The procedure allows reconstruction of an objects tomographic contrast image by assembling the frequency-dependent images.Objects at various locations along the beam propagation path are uniquely imaged on the same imaging plane using a Fresnel lens with different frequencies of the imaging beam.

The crystalline lenses of the eyes undergo mechanical, physiological, morphological and refractive changes to adjust the total refractive power of the eyes to maintain sharp visual acuity whenever an object of regard is moved toward and away from the distance at which humans typically view reading material. The aggregate changes experienced by the crystalline lenses of the eyes to maintain sharp visual acuity is referred to as accommodation. At any given time the crystalline lenses and the eyes may be regarded as being in a state of accommodation.

Most lighting level measurements are characterized in terms of illuminance.While this is useful for indoor applications, illuminance levels are not always as useful for outdoor lighting efficiency characterization.Lighting designers and researchers need a method to accurately characterize their outdoor or low level lighting applications. This invention is directed to a system for approximating the flux density of light on a human retina.Different tasks require different structures of the eye.