Eye care could be "revolutionised" by two new smartphone adaptors that can capture high-quality images of the front and back of the eye, researchers have said.
The new low-cost adaptors will mean that anyone with minimal training will be able to picture the eye and share images with experts, the developers said.
They said standard equipment used to photograph the eye is expensive and requires extensive training to use and m any GPs and emergency care medics don't have access to such apparatus.
Researchers from Stanford University School of Medicine in California developed the pocket-sized adaptor which adds a lens and lighting elements to the phone to image the front of the eye.
They created the device after building prototypes from parts purchased almost exclusively online, including plastic caps, plastic spacers, LEDs, switches, universal mounts, macrolenses and even a handful of Lego pieces.
After figuring out how to capture the front of the eye accurately, the developers turned their attentions to how they would picture the back of the eye - the retina.
They worked out the exact working distance and lighting conditions for a simple adaptor that connects a conventional examination lens to a phone.
Writing about the tools in the Journal of Mobile Technology in Medicine, one of the developers and o phthalmology resident David Myung said: " Adapting smartphones for the eye has the potential to revolutionise the delivery of eye care - in particular, to provide it in places where it's less accessible.
"Whether it's in the emergency department, where patients often have to wait a long time for a specialist, or during a primary-care physician visit, this new workflow will improve the quality of care for our patients, especially in the developing world where ophthalmologists are few and far between.
"A picture is truly worth a thousand words. Imagine a car accident victim arriving in the emergency department with an eye injury resulting in a hyphema - blood inside the front of her eye. Normally the physician would have to describe this finding in her electronic record with words alone.
"Smartphones today not only have the camera resolution to supplement those words with a high-resolution photo, but also the data-transfer capability to upload that photo securely to the medical record in a matter of seconds."
Assistant professor of ophthalmology Robert Chang added: "Think Instagram for the eye.
"With smartphone cameras now everywhere, and a small, inexpensive attachment that helps the ancillary health-care staff to take a picture needed for an eye consultation, we should be able to lower the barrier to tele-ophthalmology."