The visual phenomenon you are describing, where you see scattered flakes of "falling glitter" in your peripheral vision, is often referred to as "floaters" or "eye floaters." Floaters are common and usually harmless visual disturbances that many people experience at some point in their lives.
Floaters appear as small, semi-transparent or cloudy spots, lines, or specks that drift across your field of vision, especially when looking at a bright background, such as a clear sky or a white wall. They may seem to move when you try to focus on them directly but tend to drift away when you attempt to look directly at them.
The appearance of floaters is caused by tiny clumps of gel or cells within the vitreous, a gel-like substance that fills the inside of your eye. As we age, the vitreous can become more liquid and develop stringy, web-like strands or clumps. These shadows cast on the retina (the light-sensitive tissue at the back of your eye) create the visual sensation of floaters.
In most cases, floaters are benign and do not require treatment. They are more of a nuisance than a health concern. However, if you suddenly notice a sudden increase in floaters, flashes of light, or a shadow-like curtain in your field of vision, it could be a sign of a more serious condition, such as a retinal detachment. In such cases, it is essential to seek immediate medical attention to rule out any potential vision-threatening issues.
If you're concerned about your floaters or experience any changes in your vision, it's always a good idea to schedule an eye examination with an optometrist or ophthalmologist to ensure that everything is normal and there are no underlying eye health issues.