Most tools used by Optometrists may appear intimidating to a regular person. No wonder most people avoid regular checkups and scheduling appointments with an eye doctor. Although the devices may look scary, they are absolutely painless and comfortable to use. Doctors use these owing to the efficiency and accuracy they offer during the diagnosis of eye health.
Here’s a list of standard Eye Testing Apparatus and tools used by both ophthalmologists and optometrists during eye examinations:
Tonometer
This is one of the oldest devices used by opticians. It serves as a tool for measuring fluid pressure inside the eyeball. Eye pressure should not increase beyond a point. In case, they do, they may cause permanent damage to the optic nerve (glaucoma). Tonometer touches cornea gently to measure the pressure of the eye. Air -puff tonometer is also used by doctors. This tool blows air into the eyes for accurate measurement of eye pressure. It can be used for a glaucoma test.
Eye Testing Drum
This drum is a rotating instrument used for testing vision. The patient is asked to sit facing the wall of the drum. The drum has its interior surface striped so that while rotating, the eyes of patient are subject to a moving visual field without the patient having to move.
Phoropter
It is a basic tool used commonly by optometrists. A phoropter measures the refractive error for determining number of eyeglass for the patient. The patient is made to sit in front of an eye chart at a given distance. The practitioner applies different lenses to patient’s eyes while asking which lens allows him to see well. The accurate prescription depends on feedback of patient.
Retinoscope
Under situations where the patient is unable to give feedback to the optometrist, a retinoscope serves the purpose. Inability to give feedback may be due to certain restrictions such as mental or physical ailment. Babies and toddlers are also unable to give accurate feedback. A retinoscope helps with the measurement of the refractive error. This determines the right prescription of contact lenses. The apparatus comprises of a mirror that throws light into the eyes. It also consists of a hole in the center through which the eyes are tested.
Autorefractor
It is used for measuring the refractive error of the eyes for accurate prescription of lenses. The patient is instructed to look into the machine with a picture that moves in and out of focus. Later on, the device takes readings to determine time when the image is on the retina.
Snellen Chart
This is a physical or digital chart. It is placed around twenty feet or six meters away from the patient. The tool consists of alphabets in decreasing order of size. The patient is asked to read the chart with one eye covered while determining the accurate prescription of the other eye. Patient is asked to read the smallest letters while the optometrist keeps applying different lenses in metallic eyeglass frame. This adjustable trial frame is mounted on patient’s face.
Retinal Camera
It is used for capturing an image of interior surface of patient’s eye, mainly the retina. Retinal camera is a dedicated low powered microscope. It comes with a camera attached to it. The apparatus facilitates ophthalmologist to study the retina of patient and monitor changes in the retina over a span of time. It is also helpful in diagnosing diseases.
Opthalmoscope
Optometrists use this tool to examine the interior of the eye. It comprises of a light source and built-in mirrors and lenses. This helps in examining the retina. Prior to using the tool, the eyes of the patient are dilated using eye drops. This allows a practitioner to get a clear and detailed view of the interior of the eye. It also helps them determine signs of possible eye diseases.
