DEVICE: AUTO REF/KERATO/TONOMETER (04987669100066)

An ophthalmic, line-powered, measuring instrument used for determining the intraocular pressure (IOP) by exerting an external force against the eye which provides a reading of the resistance of the tunica of the eye to deformation (the extent of corneal indentation) which is expressed in millimetre(s) of mercury (mmHg). It typically has no contact with the eye and can use various techniques, e.g., the air-puff tonometer records deflections of the cornea from a puff of pressurized air; the applanation tonometer records the indentation pressure in thousands of a second. It is used for the diagnosis of glaucoma, designed for table top use and may provide the data on a screen and/or a print-out.

A bench-top, mains electricity (AC-powered) ophthalmic instrument designed to measure the curvature of the anterior surface of the cornea, particularly for determining the presence, extent, and axis of astigmatism (an error of refraction in the eye due to the cornea being unequally curved in different directions, so that rays of light in different meridians cannot be brought to focus together on the retina). It actually measures the radius of curvature in millimetres but typically displays it in dioptres. It is used mainly for contact lens fitting and for intraocular lens power determination prior to cataract surgery. This device is also known as an ophthalmometer.

An electrically-powered, ophthalmic device designed to be used by a healthcare professional to objectively measure the refractive error of the eye (the inaccuracies of focusing light upon the retina) by measuring how light is changed when it enters the patient's eye(s). The device emits light into the eye and detects the light reflection which is measured for sphere, cylinder, axis and/or high order aberration measurements, typically measured in dioptres (the reciprocal of the focal length of the lens expressed in metres). Also known as an aberrometer, the device uses this information to automatically calculate the lens prescription needed to correct the patient's vision.