The unsuitability of the retina of the eye as a reflective projection screen for image observation causes objective optometry to be expensive and of limited accuracy. The subjective assessment of image quality is the only way to make full use of the resolution capability of the eye. A subjective optometer for home use is disclosed with ample accuracy and confidence for mail order of prescription glasses. It overcomes the disadvantages of subjective optometry and is able to measure the refractive errors to the resolution limit of the eye, which is of great importance for the present state and relief of ametropia. Electronic recording and connectivity can be provided as an option.
