The bio-microscope and the slit lamp form a two part instrument that your eye doctor uses during a comprehensive eye exam to view both the anterior or front portion of your eye and your eye lids at high magnification. The slit lamp uses a high intensity light source to illuminate the front of your eye or lids. The width of the beam is adjustable from a full beam to a thin slit of light, enabling the doctor to better evaluate the health of your eyes.
The bio-microscope is basically a stereo microscope tilted forward to look at the lids and lashes and the front of your eye. With dilation solution and special hand held lenses, your doctor can focus on the back of your eye as well, to view the retina internal structures.
Your doctor might also apply orange fluorescein eye drops and use a cobalt blue filter on the slit lamp. The die, injunction with the blue light, enables your eye doctor to better see any imperfections on the cornea, white of the eye and the lids. These imperfections may include signs of dryness, scratches, infections or eye injuries.