short sight 
noun [mass noun]
The inability to see things clearly unless they are relatively close to the eyes, owing to the focusing of rays of light by the eye at a point in front of the retina. Also called myopia.My father had short sight and lost his eyesight due to glaucoma....
- After an eye test, a two-year-old child was found to have short sight and power of the glass to be worn is - 12.
- Defective vision due to short sight or long sight can be corrected by wearing spectacles, contact lenses or by LASIK.