Do you have trouble reading objects from a distance or up-close? Then it is likely that you have a refractive error, a condition wherein the shape of your eye prevents sufficient light from focusing on your retina. Refractive errors come in one of four major types: myopia, hyperopia, presbyopia, and astigmatism. You need to go to reliable eye doctors and get tested to get proper diagnosis.
Myopia is better known as nearsightedness, and happens when the distance between your cornea and retina is too long, causing light to shine in front of your retina rather than on it. Meanwhile, farsightedness or hyperopia occurs if the distance between the cornea and retina is too short, forcing light rays to come into focus without even reaching your retina. Obviously, these two errors can be fixed by optimizing the distance between the cornea and the retina.
Presbyopia, on the other hand, is a type of nearsightedness caused by aging, and usually afflicts people aged 40 and above. Meanwhile, astigmatism is caused by an uneven cornea, forcing the images that you see to appear blurry and stretched out. These two can be treated with the help of refractive surgeries or simply by wearing prescription eyewear.