How can age-related macular degeneration (AMD) be described?

Age-related macular degeneration (AMD) is primarily characterized as a progressive disease that affects the retina, specifically the macula, which is the central portion responsible for sharp, detailed vision. In AMD, the macula's structure deteriorates over time, leading to a gradual loss of central vision while typically preserving peripheral vision. This condition is one of the leading causes of vision loss in older adults and can manifest in two forms: dry and wet AMD, both of which contribute to the degeneration and loss of photoreceptor cells in the macula.

The other choices do not accurately describe AMD. For instance, night blindness relates to issues with the rod cells in the retina or problems with the overall functionality of the retinal pigment epithelium, rather than the specific degeneration of the macula. Refractive errors affecting distance vision pertain to conditions like myopia or hyperopia, which involve the eye's focusing ability but are not connected to retinal degeneration. Lastly, conditions affecting the cornea involve different issues related to the front part of the eye, such as corneal abrasions or keratoconus, rather than the degeneration of retinal tissues seen in AMD.