Figure shows a simplified model of the eye that is based on the assumption that all of the refraction of entering light occurs at the cornea.The cornea is a converging lens located at the outer surface of the eye with fixed focal lenght of nearly 2 cm. Parallel lights coming from infinite distance refract from cornea have been shown to produce a focused image on the retina.The retina then transmits electrical impulses of formation of image along the optic nerve to the brain.Myopia and hyperopia are two common defects of eye. Myopia or near sightedness occurs when lights coming from distances after the refraction from the cornea focuses the image of a distant object in from of the retina.Hyperopia or far sightendness occurs when after refraction cornea focuses the image of nearby object behind the retina. Both these types of defect are corrected by using lenses of suitable focal length and nature, such that the combination of additional lens and cornea together form a focused image again on the retina.The distant object may be considered to be placed at infinite distance, then image distance from cornea (v) isevaluated by the following relationship :1/f + 1/f1 - x = 1/v, fc = focal length of corneaf1 = focal length of correcting lensx = Distance between cornea and additional lens.How far should the retina be from the cornea for normal vision?(A) 1.0 cm(B) 2.0 cm(C) 4.0 cm(D) 0.5 cm