When any one or two of the causes of refractive error happens, the following vision problems arise:
- Nearsightedness (myopia) – far away objects look blurry but nearby objects appear sharp
- Farsightedness (hyperopia) – objects up close look blurry but objects at a distance appear sharp
- Astigmatism – objects up close or faraway look blurred or distorted
- Presbyopia – objects far away appear sharp but close objects appear blurry due to aging natural lens