The autorefractor is a medical equipment used for objective and automated assessment of patient refractive error. It is one of the most commonly used equipment in ophthalmology clinics. It is a must-have device in optical shops and Optometric practice because of its ease of use, speed, reasonable accuracy and repeatability of results. Proper care and regular maintenance is crucial for long life of the Autorefractor. Common problems faced with and autorefractor repair needs include light source/electrical issues, mechanical and control system issues and measurement accuracy / calibration issues.
An autorefractor (AR) offers a means to provide a starting point for subjective refraction when optometrists need to perform a comprehensive eye examination in minimum time possible. Several AR models also provide keratometry measurements (The equipment is called ARK – Autorefractor Keratometer), including corneal mapping and detect corneal irregularities.
How does an Autorefractor work?
The autorefractor projects the fixation target image into the patient eye. The rays from this image pass through the lens and strike the patient retina. Some of the light reflects from the retina and exits the eye. If there is refractory error in the patient, the eye’s lens distorts the “return” image. The refractive error is calculated by analysing two rays. There are three most common methods for refractory error analysis – (1) image quality analysis, (2) Scheiner disc principle and (3) retinoscopy. In the Scheiner disk method for determining refractive error – A disk with two holes is placed in front of the pupil. When viewing the target image, the image perceived by the patient will be dependent upon the refractive state of the eye. People with no visual defect see a single point, while those with refractive error will see two distinct sources.
Main Components of Autorefractor
The Autorefractometer has three main components: an infrared light source, a fixation target and a Badal lens system.
Infrared light source – An infrared light source with a frequency of around 800-900nm is used in autorefractors, as it allows good ocular transmission at the sclera. This light is invisible to the human eye, so there is no discomfort to patient or any effect on pupil diameter or accommodation response.
Fixation target – Most autorefractors use a ‘fogging’ target to relax accommodation.’ Fogging’ targets range from simple pictures to scenic fixation charts for optimal results making fixation easier.
Badal lens system – Most autorefractors use an automated Badal optical system to determine the refractive state of the eye. In an autorefractor, an infrared light source is projected via a beam splitter and the Badal lens system to form the optimal focus of the slit image on the retina. The reflection of the slit image passes out via the beam splitter to reach the light sensor.
Common Autorefractor Repair Issues
Here, we will talk about common problems faced while using Autorefractor and possible causes. Most of the repair issues in Autorefractor can be grouped under the following 3 main categories:
- Electrical
- Device is not turning ON – It could be power cord problem, power switch failure or blown fuse.
- LCD display does not function properly – You may be seeing a black screen, white screen or blurred screen. The screen may intermittently disappear or start rolling as shown below.
- Indicator lamp failure
- Mechanical & Control Systems
- Main body of the machine is not moving properly – up/down or lateral movement is impacted
- Printer is not working
- Locking structure malfunction
- Poor Key response or buttons not functioning
- Measurement accuracy & calibration problems
- Device refraction results (spherical power, astigmatism power or PD value) are not accurate or consistent- requires calibration
- Keratometry does not work, or is not accurate or consistent
Reliable Autorefractor Repair Services in India
Should you face any of the above problems with your Autorefractor, contact us at 7019759765 or 8971223957! PrimedeQ can assist you with bulb or fuse replacements, power supply problems, knobs and lever malfunctioning, board replacements or any other types of Autorefractor repair and general servicing.
PrimedeQ is an e-Marketplace for buying, selling, renting, servicing and spares of medical equipment. We offer all types of used / refurbished medical equipment , including Autorefractor, Slit Lamp, A-Scan machine and other Ophthalmology equipment, endoscopes, OT equipment, Laparoscopic Equipment, Lab equipment, X-Ray, TMT, ECG, anesthesia machine, ultrasound machines etc. We offer repair services for all types of medical equipment including Lab equipment, microdebrider, laparoscope , x-ray tube, rigid and flexible endoscopes as well as EUS (Endoscopic Ultrasound Units) and ultrasound probe etc.
