List four common defects of vision that can be corrected with the use of spectacles.

(N/A) The four common defects of vision that can be corrected with the use of spectacles are:
$(i)$ Myopia (nearsightedness): Corrected using concave lenses.
$(ii)$ Hypermetropia (farsightedness): Corrected using convex lenses.
$(iii)$ Presbyopia: Corrected using bifocal or progressive lenses.
$(iv)$ Astigmatism: Corrected using cylindrical lenses.