Why do nearsighted people need accommodation in order to focus on objects, if the vision is focused in front of the retina (too much refractive power), doesn't accommodation worsen the vision in this case?
Great question! You have good insight and are quite right: myopic (nearsighted) people can see up close even after becoming presbyopic!
This is because the default focal point for a nearsighted eye is abnormally close -the same reason their distance vision is blurred. This can come in quite handy in middle-age and older when the eye's natural lens slowly hardens. This hardening makes the natural lens increasingly resistant to the surrounding muscle's attempts to squeeze it into the thicker shape necessary to focus up close.
So, unless the myopia is really extreme or is complicated with astigmatism, a middle-aged myope (nearsighted person) can just take off his distance glasses and read. They often prefer this to bifocals or progressive glasses because it doesn't require lining up the visual axis just right.
One of the most common complaints of nearsighted LASIK patients over 40 or post-cataract/IOL nearsighted patients is the loss of that "natural" near vision, albeit with the gain of good distance vision. A responsible eye doctor will demonstrate this to a prospective surgery patient with trial lenses so there are no surprises.
Written by J. Trevor Woodhams, M.D. - Chief of Surgery, Woodhams Eye Clinic