When you spend time by the pool or at the beach, you may notice light glare reflected into your eyes from water or flat surfaces — even when wearing a high-quality pair of sunglasses. For some, this glare can cause pain and discomfort and can sometimes lead to short-term visual impairment.
Polarising or polarised sunglasses can help to reduce the impact of glare on the eyes. To help you understand if polarising sunglasses might be right for you, we’ll take a closer look at how they work to reduce glare and protect your eyes from the sun.
What are polarising sunglasses?
Polarising sunglasses contain lenses designed to reduce light glare from surfaces such as water, sand and snow. When sunlight is reflected from these surfaces into your eyes, it can distort the true colour and shape of objects, making them harder to distinguish. This light glare can dazzle the eyes, which can cause pain, discomfort and sometimes short-term visual impairment.
Prior to moving to Spain, many expats may not have noticed a particular sensitivity to sunlight. However, if you now experience symptoms of light sensitivity, or photophobia, during sunny days at the beach, it might be worth considering a pair of polarising sunglasses.
How do polarising sunglasses reduce glare to protect your eyes?
Polarising lenses contain a special chemical layer which acts as a filter for light. The molecules of this layer are arranged to partially block some of the light from passing through the lens. Much like a shutter blind, they only let light through the gaps in-between the molecules. This means that only light rays that approach your eyes vertically can fit through those openings, and horizontal light waves reflected from the sea or smooth sand will be blocked. As a result, the image you see with polarising lenses is a bit darker than usual, but objects look clearer, and details are easier to see.
When not to wear polarising sunglasses
There are a few instances when polarising sunglasses are not suitable to wear. For instance, you may have difficulty seeing images on LCD (liquid crystal display) screens when wearing polarising lenses — such as car dashboards, mobile phones, televisions and some watches.