6 month warranty Excellent condition The NIDEK ARK-500A is an autorefractor/keratometer which contains both a refractormeter and keratometer in one unit. The refractometer objectively measures refractive errors of sphere, cylinder,...
The NIDEK ARK-500A is an autorefractor/keratometer which contains both a refractormeter and keratometer in one unit. The refractometer objectively measures refractive errors of sphere, cylinder, and axis for lenses that correct the patient’s vision into emmetropia. The ketatometer measures the corneal curvature radius (corneal refractive power), principal meridian direction and corneal cylendrical power. Refraction is mainly performed as a reference for lens prescrition to correct the visual acuity using glasses or contact lenses.
The corneal curvature radius measurement is mainly performed for the following purposes:
The device offers the following features in addition to the above features: