A slit lamp device for use in an ophthalmoscope includes one or more light sources for providing a light path comprised of one or more beams of: visible light and infrared (IR) light； a slit lamp control mechanism along the light path for receiving the one or more light beams and forming the one or more light beams into a slit light beam； the slit lamp control mechanism further controlling the width of the formed slit light beam； a first, narrow slit passes visible light through the slit control mechanism and a second, wider slit passes IR light though the slit control mechanism.
