The Folding Phoropter is a novel device developed by the Srujana Center for Innovation, L V Prasad Eye Institute, Hyderabad to combat the disproportionate access to tools for screening for refractive error in low resource areas. This device is extremely low-cost, disposable, easy to assemble and open-source, which means anyone can build their own following the instructions.
Inspired by Dr Manu Prakash's "Foldscope" and the Google cardboard, we re-imagined a phoropter into the most basic screening device which could be easily and scalably fabricated, improved upon and used for the betterment of eyecare. Get involved! Send a mail to ashishjain [AT] lvpei.org or joshi [AT] lvpei.org
A simple device made using origami. Using our data-driven approach, we have calibrated this device on the most commonly observed refractive error ranges. Easy to understand, intuitive to use.
USABLE BY ALL
The lenses need to be placed in their designated positions and fold along the lines. The two parts line up inside one another, resembling a telescope. The patient needs to look through the device a fixed distance away from the designated target, and move the outer chamber inwards until the image just comes into focus.
RELIABLE PREDICTIONS OF REFRACTIVE ERROR
We collected data from 100 subjects and measured their refractive error using our device, subjective refraction and objective refraction at the clinic. The adjoining plot shows the comparison between our device's readings and the gold standard (taken as ground truth). Patient data is represented by opaque dots (darker color indicates overlapping of multiple samples with the same measurements). The line of best fit and the standard error of the mean are represented by the blue line and gray shade, respectively. There is a strong correlation between JULIA readings and standard readings (Pearson correlation: rho = 0.8, p < 1e-16).
EASY TO ASSEMBLE
Our device is extremely easy to assemble, it can be put together in a matter of minutes without prior training. Simple origami is needed, similar to folding a takeaway parcel box or an envelope.
Let's come together to make possible universal access to basic eyecare!
BUILD YOUR OWN
ORDER YOUR OWN
If you are interested in purchasing the device (which includes all parts and an instruction manual) please send a mail to srujana [AT} lvpei.org
BECOME A CONTRIBUTOR
Are you interested in helping us improve the design? Are you an optometrist, engineer, designer or an inventor who is keen to contribute to democratizing access to quality eye care? Send us a mail at srujana [AT] lvpei.org