Most cardiovascular or metabolic disorders show up as vascular pathology on the retina. For instance, Diabetic retinopathy (DR). This is a potentially vision-threatening conditions, where patches of one's retina lose the ability to react to light. This causes patches in one's vision, and if left unchecked, can soon be an irreversible loss of vision. These disorders need to be picked up early and can be treated. However, they require two things - the ability to capture high quality photographs of one's retina, and the ability to interpret those images and diagnose conditions. The first one is done using extremely high quality machines in the market, which are usually very expensive. The second is usually done by a trained clinician (ophthalmologist). Both of these are extremely difficult to get access to in resource-constrained areas or part of large-scale public health screening programs, where they are needed the most.
On the left is a retinal (fundus) image of a normal healthy individual, taken using a high-end benchtop fundus imaging tool. Notice the bright white optic disk on the right, the blood vessels emanating from it (which supply blood to the retina) and the dark spot slightly off center, which is the fovea (responsible for central vision through which we do complex visual tasks like reading).
On the right we have a fundus image of an individual suffering from Diabetic retinopathy. Notice the flaky white spots all over the retina. These "exudates" are deposits which causes "patches" to form in one's vision. Diagnosing this condition is impossible without a good quality fundus imaging camera, which typically costs a few thousand dollars and is extremely large and heavy - definitely not a good solution for field screening programs.
What does this mean for the patient? Those small white spots lead to "blind spots" in one's field of view. The image on the left simulates vision for someone suffering from this condition. If left unchecked, this can lead to permanent vision loss and the inability to perform routine tasks. India, where we are building this product, has the dubious reputation of being the diabetes capital of the world - about 63 million people suffer from diabetes, with this figure likely to go upto 80 million by 2025. About 37% of urban south asians suffer from diabetes or pre-diabetes and are at risk of developing DR. Timely treatment can reduce risks by more than 90%, however symptoms of vision loss only present themselves after significant progression of the disease.