Light brightness and dimness, how do the eyes allow us to see well under different brightness? When we go into a dark theater, after a few moments the eyes adapt, and we find our seat. When we go outdoors on a sunny day, our pupils narrow, and we see better. The eyes constantly adapt throughout the day making vision better as lighting changes.

Around 1900, the ERG was invented and greatly measured the peripheral retina but not the center retina, the fovea. In fact, many scientists thought the fovea had no measurable measurement and others thought it was too fast to measure. Selig Hecht, PhD in 1921 measured a single human fovea with a red-light adaptometer. In 1953 and 1989 others measured the adaptation in only one eye of people. The fovea has only cone receptors that measure color and black and white, the peripheral retina has only rod and cones that measure only black and white. 

Using a different method, Albert J. Hofeldt, MD patented the measurement of the foveal cones in two eyes, first one eye and then the other eye. He developed two computer patents to measure white light adaptation and another measuring-colored light adaptation. AMA Optics supplied the iPhones and apps to JS Kane, M Gaspich, A Gold, H Pichardo and SA Kane, PhD. MD, their results of normal people showed it to be fast, easy, reproduceable, unaffected by bright light or pupil size and recovery time increased with aging. We just completed testing normal and diseased eyes and the results will be published soon. 

Currently there is a test that measures the peripheral retinal and seems to predict advancement of macular degeneration in the future, but since it does not measure the fovea, it will never measure foveal function.

The MacHealth and the MacDx are my devices and measure the fovea.  The MacHealth IOS app is for all people to test on their iPhone. One test on both eyes takes 2 minutes, results are recorded, stored and transferable.  To repeat 3 tests, take 6 minutes.  People who follow their fovea, usually test the fovea every 3 months. This is the first digital test for macular problems tested at HOME on an iPhone or iPad. Online purchase of 30 tests for 99 cents, which is 3.3 cents per bilateral test.  For now, we take calls to help with learning the test, call 305 389 0928, ask for Albert.