Trouvez le problème de vue associé à chaque définition :
1- Inability to see things clearly unless they are relatively close to the eyes. 2- Seeing objects at a distance clearer than those near at hand. 3- A refractive error of the eye in which parallel rays of light from an external source do not converge on a single focal point on the retina. 4- Inability to distinguish one or several colours.