Sentence:  The single-imaging optic of the mammalian eye offers some distinct visual advantages. Such lenses can take in photons from a wide range of <WSD>angles</WSD>, increasing light sensitivity. They also have high spatial resolution, resolving incoming images in minute detail. 
Meaning of the word marked with <WSD> tags:  (measure of such a figure) The measure of such a figure. In the case of a plane angle, this is the ratio (or proportional to the ratio) of the arc length to the radius of a section of a circle cut by the two rays, centered at their common point. In the case of a solid angle, this is the ratio of the surface area to the square of the radius of the section of a sphere.