We’ve written reviews on numerous Canon instruments and we’re always greeted with well-engineered, accurate, and advanced instrumentation every time. So we’re happy to report that Canon’s first ever Autorefractor/Keratometer is no exception to our rule. In fact, the RK-F1 is so brilliant in every category we rank it towards the top of our (no longer produced) best Autorefractor list. The RK-F1 is just so brilliant, we have to remind ourselves that the device was first manufactured over 9 years ago– it still holds onto a black and white screen, weighs more than a mountain, and looks like a boat standing on its bow- but that’s all glossed over from the moment you flip the switch and enlighten yourself to the fully automated settings of the RK-F1. Many Autorefractors preach automation through software, still requiring manual alignment from the operator; Canon’s RK-F1 is fully-automated, meaning you literally just have to push one button. That button is labelled ‘start‘, and once you press it, the machine does the rest. It must be the most fully-automated autorefraction units ever built, and therefore allows just about anyone to operate it with or without experience. The instrument does have a unique rollable joystick, which can control the optic head for a manual capture, and a motorized chin rest controlled from two buttons on the front-end, however it’s all unnecessary given its autonomous ability; it’s the closest thing eye care has to a self driving car. The RK-F1 checks all the other necessary boxes as well: it’s phenomenally accurate on pupil’s down to 2.0mm, quite robust compared to competitors units, and offers ancillary measurement tools such as corneal diameter, and Peripheral Keratometry.
OUR TAKE: One of the world’s ‘most-automated’ Autorefractors ever made. Its motorized optical head does everything for you, with style and accuracy, all while being incredibly robust.
#1. Just Press Start
The RK-F1 is fully automatic, and motorized in almost every way. A large step above from most Automated Refractors that although perform objective refractions, still require manual adjustment and alignment from the operator. The RK-F1 does it all– auto-detects which eye its testing, auto-aligns the optical head to find the center of the cornea, auto-focusses, and auto-fires when everything is set. When Canon produced the first brochure for the device, their tag one was simply “Just Press Start–” perhaps the most true statement about an ARK we’ve ever heard.
At first, this sounds too good to be true. After all, it’s hard to imagine an Automated refractor being absolutely that- completely automated. But even in our testing, we found that the Canon lives up to its tagline. We were able to refract a dozen individuals in all less than 5 minutes (in summation) with merely hitting the ‘Start’ button 12 times. This was all easily accomplished without adjusting the chin rest or performing any manual adjustment.
#2. Ultra-Wide Dioptric Range
Canon also wasted no effort in the instrument’s interpreting abilities, giving it one of the widest dioptric ranges possible. The unit allows spherical testing from -30D to +22D, and an eye opening 5.5mm to 10mm in terms of radial curvature. Even our brand new generic ARKs struggle to reach even two-thirds of that range. The RK-F1 is a rare example of an instrument that is incredibly user friendly, all while be all equipped and over qualified for the job.
#3. Peripheral Keratometry
The only reason we can really think to still have a manual keratometer is the granting ability of recording keratometric values outside the very center of the cornea. But with the Canon, that’s no longer necessary as its built-in peripheral keratometry mode provides accurate measurements for examining oblique astigmatism as well as for determining the best fit for contact lenses. The RK- F1 can be used to make a series of measurements at a 30 ̊ angle from the eye’s center, along the attentive meridians. Full auto-alignment technology (as mentioned above) streamlines this procedure, as all the operator needs to do is press the Start button to confirm that the eye is properly fixated on each measurement point. Readings for the corneal astigmatism axis and corneal eccentricity (E) are automatically included on the printout.
#4. Retro Illumination
Canon has also considered illumination options for its devices, and realizes that most ARKs struggle with providing enough infrared light to offer detailed views of the cornea (and beyond). Through retroillumination, the RK-F1 brings you an extremely detailed view of the eye that’s particularly useful for identifying cataracts, vitreous opacity, scars, and other serious eye problems. Dust or scratches on the examinee’s contact lens are also clearly visible in this mode. The RK-F1 stores up to two images, which can be selected and displayed on the monitor at a magnified size for observation.
The cornea flattens towards its periphery, and the rate in which it flattens differs between individuals. This is obviously crucial health data for contact lens fitting. The RF-10 allows Keratometric measurements at a 30 ̊ angle from the eye’s center, along the attentive meridians, to provide alternative K readings exclusively from the patient’s corneal center.
A 2.0mm pupil diameter. This is consistent with most other Autorefractors.
10 measurements (at one time) per eye.