There are two types of AMD: wet (neovascular) and dry (atrophic). It's possible to experience the wet type in one eye and the dry type in the other; in addition, the dry type can progress to wet in approximately 10-15% of cases.

The dry/atrophic type affects approximately 85-90% of individuals with AMD. Its cause is unknown, it tends to progress more slowly than the wet type, and there is not — as of yet — an approved treatment or cure. In dry AMD, small white or yellowish deposits, called drusen, form on the retina, beneath the macula, causing it to deteriorate or degenerate over time.

The wet/neovascular type affects approximately 10-15% of individuals with AMD, but accounts for approximately 90% of all cases of severe vision loss from the disease. In wet AMD, abnormal blood vessels under the retina begin to grow toward the macula. Because these new blood vessels are abnormal, they tend to break, bleed, and leak fluid, damaging the macula and causing it to lift up and pull away from its base. This can result in a rapid and severe loss of central vision. Although its cause is unknown, several new treatments are now available for wet AMD.

You can read more about both types of AMD at Macular Degeneration International, Macular Degeneration Partnership, and Macular Degeneration Support, where you can also view a retinal photograph of dry AMD and drusen and a retinal photograph of wet AMD (also called exudative).