RI, or Rod Intercept, as measured by the AdaptDx is the time it takes in minutes for your vision to adapt from bright light to darkness. Dark adaptation is greatly impaired in the early stages of macular degeneration. As a result, your RI can provide the earliest warning sign of age-related macular degeneration (AMD) before it affects your vision.
Trouble seeing at night is the first symptom of age-related macular degeneration (AMD), a progressive disease that affects your central vision and is the leading cause of adult blindness in the developed world.
Patient education video explaining that night vision problems are the first warning sign of early stages of age-related macular degeneration and should be tested using the AdaptDx dark adaptometer.