The patient may accept minus lenses due to an inability to relax the accommodative system. These patients require plus lenses at near and vision therapy to relax the spasm of accommodation. For younger patients, plus lens acceptance will determine how much of the refractive error is to be prescribed. It is unusual to prescribe the full amount of correction for pre-presbyopic hyperopes. Prescribing for Astigmatism When astigmatism occurs in conjunction with spherical refractive errors, the doctor must decide whether the patient's symptoms are due to the uncorrected spherical refractive error or the uncorrected astigmatism.
Uncorrected astigmatism can cause symptoms of blurred vision, headaches, asthenopia, and nausea.
The severity of the symptoms will vary with the magnitude of the astigmatism. Patients may report difficulty with reading. Patients may also report monocular double vision or the presence of ghost images. Younger patients may be able to compensate for their uncorrected astigmastism by accommodating within the interval of Sturm. This will become more difficult as the patient ages.