The refractive power of the eye’s optical system is dependent upon the curvature of the optical surfaces. The curvature of the surfaces of the lens within the eye can be increased - thereby increasing the power of the eye - by a process known as accommodation. Although accommodation is used by emmetropes (those with no refractive error) to change their focus from a distant to a near object, it can often also be used by hypermetropes to overcome their refractive error. If it cannot, then the error is corrected by positive spectacle, or contact, lenses, or by refractive surgery.
An uncorrected hypermetrope will be able to see clearly between infinity
and their ‘near point’ (the closest they can see clearly). This ‘near
point’ will generally be further away than that of an emmetrope.
If some of the person’s accommodation is being used to overcome the refractive
error, there is less available for near-focusing.
Consequently, a hypermetrope may suffer from presbyopia
at an earlier age than normal.
Generally, uncorrected hypermetropes will not complain of blurred distance vision, but they may suffer from eyestrain and headaches (because of the continuous use of their accommodation) as well as blurred near vision.