What is described herein is a neutral pH, VOC-free biocidal composition of 1,2-benzisothiazolin-3-one which is stable at low temperatures for an extended period of time. The ophthalmoscope includes a handle within which there is situated a printer to provide an instantaneous permanent record of an image as viewed. A control circuit is connected between the voltage input end of the power amplifier and the feedback pin; the control circuit includes a control voltage, where the control voltage adjusts the voltage at the voltage input end of the power amplifier through the control circuit and the control voltage is variable. The separator in combination with the electrolyte has an area specific resistance less than 2 ohm-cm2.