Once the person has dilated pupils, the doctor will repeat the eye exam. This time they will keep a particular lens close to the eye. The procedure is painless, although there may be a brief stinging sensation during the application of the eye drops. For this purpose, many doctors use a “slit lamp”.
It is a special microscope and light that allow the doctor to see the eyes in 3D, both inside and out. They will use it together with an ophthalmoscope to look at the back of the eye. A slit lamp is a microscope with a bright light that is used during an eye exam. It allows the ophthalmologist to take a closer look at the different structures in the front and inside of the eye.
It is a key tool for determining eye health and detecting eye diseases. The slit lamp exam uses a tool that provides an enlarged three-dimensional (3D) view of parts of the eye. During the exam, the doctor may look at the front parts of the eye. These parts include the transparent outer cover (cornea), the lens and the colored part (iris).
The doctor can also see the front side of the thick liquid (vitreous gel) that fills the large space in the center of the eye. Routine slit lamp exams are done to detect eye problems at an early stage and to guide treatment if eye problems occur. This leaflet is for people who need to be tested for diabetic eye disease using an instrument called a slit lamp instead of a digital camera. It will then turn on the slit lamp and focus a narrow, high-intensity beam of light toward the eye.
Special lenses may be placed between the slit lamp and the cornea (or over the cornea) to help the doctor see the deeper structures of the eye. During the exam, the doctor will look through the microscope and adjust the light of the slit lamp to see certain parts of the eyes. In addition, when the slit lamp is attached to a special magnifying lens, the doctor will be able to see the retina and optic nerve located at the back of the eye.