(a) A student suffering from myopia is not able to see distinctly the object placed beyond 5 m. List two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams explain. (i) Why the student is unable to see distinctly the objects placed beyond 5 cm from his eyes. (ii) The type of the corrective lens used to restore proper vision and how this defect is correct by the use of this lens. (b) If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the lens as per the new Cartesian sign convention.