Dear Student,
The person is suffering from both Myopia and Hypermetropia. It is because the range of a normal eye vision is from 25 cm to infinity that is 25 cm is the shortest distance for the distinct vision and infinity is the longest distance for vision for a normal healthy eye. Since, the person can see the objects lying in between 50 cm to 300 cm, therefore he is suffering from both the defects.
It can be minimised by using bifocal lens that is concave lens for distant vision and convex lens for near vision.
Regards