During an eye exam, ophthalmologists have a technician gather all health information and check eye pressure and vision. The ophthalmologist will then check the health of the eyes. For these complete exams, ophthalmology offices need certain equipment, and some patients who have not had an eye appointment with an ophthalmologist may have some anxiety about what occurs. Knowing about the tools and equipment used for an eye exam can help alleviate these concerns.
Non-Contact Tonometry
Ophthalmologists need to know the eye pressure inside the eye. A high eye pressure may indicate a serious eye condition. To check pressure, the doctor or his technician may use a non-contact tonometry (NCT) machine. The patient places her chin on a chin rest, and the technician blasts a puff of air onto the surface of the eye. This does not hurt, but it may startle the patient.
Phoropter
To determine if a patient needs glasses or contact lenses, the doctor or technician will use a phoropter machine. This tool has all possible combinations of eye prescriptions. The phoropter rests against the forehead and has two circles for the eyes to look through. The doctor or technician will block off one eye at a time, changing lenses in the machine. With each lens change, the patient must determine which lens looks best.
Eye Drops
One of the most important parts of the eye exam occurs when the doctor checks the health of the eyes. In order for the doctor to have a good, clear view of the back of the eye, he must dilate the pupils. The doctor's technician will put drops in each eye that take effect within a few minutes. Ophthalmologists may also use eye drops to numb the surface of the eye for certain procedures, such as removing a foreign body or eye lash. If he suspects certain infections, or for some eye injuries, the doctor may require a yellow stain that allows him to see scratches or changes on the eye's surface.
Slit Lamp
Slit lamps are special microscopes designed specifically for the eye. These machines sit on a moveable table, and the doctor positions the slit lamp in front of the patient for the exam. The patient's chin sits in the chin rest, and the doctor moves the microscope to various positions that allows him to see the front and back of the eye. The microscope has a bright light that must be on for the slit lamp to work, but the doctor can dim the light slightly if necessary. Slit lamps also have a prism that slides in front of the microscope that will check eye pressure, a method referred to as applination tonometry because the prism gently touches the eye's surface during the measurement.
