NIDEK ARK-500A Autorefractor Keratometer
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:
- Lens prescription fro correction of visual acuity using contact lenses or such.
- Determination of the power of intraocular lenses to be implanted after cataract surgery.
- Postoperative follow-up of corneal shape.
The device offers the following features in addition to the above features:
- The ARK-500A is provided with an auto-tracking mechanism that achieves alignment in the up and down direction.
- An auto shooting function is provided; measurements take place automatically when the device is best aligned and focused.
- A moterized up and down chin rest allows the operator to easily adjust the height of the chinrest.
- A built in RS-232C interface allows data export to computers and such.
- A view comparison function and measurement ring image display function are provided.