I have amazing eyesight! Some people will call it a good visual acuity! 
Lucky! I have horrible eyesight. I have to wear glasses. Does visual acuity mean 20/20 or better?
the shape of the eyeball or the cornea, and reduced flexibility of the lens. Too high or too low refractive error (in relation to the length of the eyeball) is the cause of nearsightedness (myopia) or farsightedness (hyperopia) (normal refractive status is referred to as emmetropia). Other optical causes are astigmatism or more complex corneal irregularities. These anomalies can mostly be corrected by optical means (such as eyeglasses, contact lenses, laser surgery, etc.).
Neural factors that limit acuity are located
metres. If a person has a visual acuity of 6/12, he is said to see detail from away the same as a person with "normal" eyesight would see it from away.
Healthy young observers may have a binocular acuity superior to 6/6; the limit of acuity in the unaided human eye is around 6/3–6/2.4 (20/10–20/8), although 6/3 was the highest score recorded in a study of some US professional athletes. Some birds of prey, such as hawks, are believed to have an acuity of around 20/2;