The question of whether soft eyelashes can scratch a hard eyeglass lens is a common concern for people who wear glasses. Although it feels like constant brushing should cause wear, eyelashes are almost never the source of the fine scratches that appear on eyewear. This is explained by the fundamental differences in the physical properties of the materials involved. Understanding what actually causes the damage can help you care for your glasses and keep your vision clear.
The Physical Properties of Eyelashes and Lenses
The inability of an eyelash to scratch a lens is due to material hardness and abrasive friction. Eyelashes are composed of keratin, a soft, organic compound also found in hair and nails. Keratin is simply not hard enough to abrade the surface of modern eyeglass lenses.
Current lenses are typically made from lightweight plastic polymers, such as polycarbonate or high-index plastic. Because these materials are softer than glass, they are always treated with a durable, transparent layer called a “hard coat” or anti-scratch coating. This coating is generally a silicon-based film, like silicon dioxide, which is significantly harder than the underlying plastic. The soft keratin of an eyelash cannot overcome the hardness of this specialized coating, even with the repetitive force generated by blinking.
Common Sources of Lens Scratches
Since eyelashes are ruled out, lens scratches are caused by abrasive agents with a much greater material hardness. The primary culprits are fine particulate matter, especially common household and environmental dust. Dust frequently contains microscopic particles of hard minerals, such as silica or quartz, which are harder than the lens coating itself.
When wiping a lens that has dry dust on it, the act of wiping grinds these hard mineral particles into the surface, creating micro-scratches. This abrasive action is worsened by using improper cleaning materials like shirt tails, paper towels, or rough tissues. These materials trap the abrasive dust and drag it across the lens, leading to the gradual degradation of clarity. The appearance of these minute scratches is often mistaken for wear from blinking, but they result from friction against hard particles.
Simple Steps to Protect Eyeglass Lenses
Protecting your lenses involves eliminating friction between abrasive particles and the lens surface during cleaning. The most effective preventative measure is to always rinse your glasses under lukewarm running water before wiping them. This action safely washes away the microscopic, scratch-causing dust particles without grinding them into the surface.
Once the debris is rinsed off, use a drop of mild, lotion-free dish soap and your fingertips to gently clean the lenses, followed by a thorough rinse. Dry the lenses with a clean microfiber cloth specifically designed for eyewear. Avoid materials like paper products or clothing that can be rough or transfer oils. When not wearing your glasses, store them in a hard protective case to prevent contact with dust or abrasive surfaces.