Symptoms of Macular Degeneration
There are a variety of common symptoms across the types of macular degeneration. Each symptom will become present at different stages of progression and the speed with which they become apparent to the individual varies by person.
What is foveal vision?
Central vision, also called foveal vision, allows us to see details and is especially important in reading and driving. The fovea is the center of the macula, which is located in the central portion of the retina.1
Blurry central vision
Because the macula senses light and then sends those signals to the brain via the optic nerve, if the macula is damaged then the brain will receive atypical or missing signals, resulting in decreased visual perception or blurred central vision.2
Distorted vision (metamorphopsia)
As your macular degeneration progresses, you might notice more distortion in your central vision – black or dark shadowy spots, straight lines that look wavy, or a reduction in fine detail. Your peripheral vision is less likely to be affected as macular degeneration most often impairs central vision.
A scotoma, or a blind spot, in the center of vision, is a symptom present among the later stages of macular degeneration. The scotoma may start as a smudge and progress to a gray or black spot. The size of the blind spot can change, becoming larger as damage to the macula progresses. Typically, those with a central scotoma compensate for this by trying to “look around” the scotoma through their peripheral vision.
Change in color perception
The eye sees color and black and gray because of the cells called rods and cones in the retina. Rods are most prevalent in the periphery of the retina, and are responsible for seeing black and shades of gray; cones are mainly in the macula and enable us to see color.3
Damaged rods and cones
When you see an object, the brain interprets the signals, allowing you to identify different colors. If cones or rods are damaged, however, this affects their sensitivity and ability to detect different wavelengths of colors, thus distorting the signals that get sent to the brain.
Losing color sensitivity
When the macula is damaged, the cones begin to lose their color sensitivity and may even die completely. The first colors that will be affected are those with lower wavelengths, such as yellow, purple, and pastels; these may appear instead as shades of black and gray.3 As damage to the macula progresses, all color recognition can be affected. This is not the same as hereditary color blindness, which is a result of a genetic cause.
Difficulty seeing in low light
You may notice that you have become more sensitive to light, this is called photophobia. It may take longer for you to adjust your vision to areas with lower light, especially after being in an area with brighter light – for instance, returning to a darker house after being outside in the sun. You might also find yourself turning on more lights inside than you used to in order to see better and perform everyday activities.
Nearby objects seem far away (micropsia)
Micropsia is a common symptom with disorders of the macula. It is the perception that objects are smaller than they actually are.4 This can make nearby objects appear like they are further away, because of their reduced size. This can affect various practical abilities such as reading, facial recognition, and driving.