Abstract: A digital imaging system processes digital images of a subject's fundus and/or pupils to determine pupil edge region pixels. Pupil edge region pixels are removed and a glint area is identified and interpolated over. Resulting images can be processed to determine a pixel intensity distribution slope. Using the pixel intensity distribution slope, refractive error determinations can be made.

Abstract: A digital imaging system processes digital images of a subject's fundus and/or pupils to determine a pupil edge. Two regions of a digital image are evaluated to determine a threshold value. Typically, the two regions are selected such that each region would usually not include artifacts. The threshold value can then be used to identify a pupil-iris threshold in the digital image. Based on the pupil-iris threshold, pupil edges are identified.

Abstract: A system for conducting an examination of the eyes of a subject includes an examination instrument which emits light at infrared wavelengths, and a shield. The shield provides shielding of the subject's eyes from visible wavelengths. At least a portion of the shield is transparent to the infrared wavelengths emitted by the examination instrument. A related method of conducting an eye examination on a subject includes the step of providing a shield which is transparent to infrared wavelengths but nontransparent to visible wavelengths. The method also includes the step of carrying out the examination with an instrument which is located on the examiner facing side of the shield and which emits the infrared wavelengths to which the shield is transparent. One variant of the method determines parameters relating to the subject's eyes and/or vision using only information considered to be valid, validity being based on the subject's pupil diameter.

Abstract: A system for conducting an examination of the eyes of a subject includes an examination instrument which emits light at infrared wavelengths, and a shield. The shield provides shielding of the subject's eyes from visible wavelengths. At least a portion of the shield is transparent to the infrared wavelengths emitted by the examination instrument. A related method of conducting an eye examination on a subject includes the step of providing a shield which is transparent to infrared wavelengths but nontransparent to visible wavelengths. The method also includes the step of carrying out the examination with an instrument which is located on the examiner facing side of the shield and which emits the infrared wavelengths to which the shield is transparent. One variant of the method determines parameters relating to the subject's eyes and/or vision using only information considered to be valid, validity being based on the subject's pupil diameter.

Abstract: A digital imaging system processes digital images of a subject's fundus and/or pupils to determine a pupil edge. Two regions of a digital image are evaluated to determine a threshold value. Typically, the two regions are selected such that each region would usually not include artifacts. The threshold value can then be used to identify a pupil-iris threshold in the digital image. Based on the pupil-iris threshold, pupil edges are identified.