Babbage Ophthalmoscope

Although the Helmholtz ophthalmoscope is recognized as the first practical device, Charles Babbage, the British mathematician, conceived of one in 1847. He built the device, but when physicians could not see an image, he abandoned the device. Unknown to Babbage, the instrument would have worked perfectly with a different lens between the observer and the mirror. Interestingly, the Babbage ophthalmoscope resembles Brunton’s device.

Babbage ophthalmoscope
Image of a Babbage ophthalmoscope