Have you ever felt blinded by intense light?
Most of us have experienced blindness by intense straight light coming from either headlight of vehicles, the Sun or so.
Despite all the efforts by your pupil, eyelids, and shrugging eyebrows to restrict the excess light from blinding your vision, your natural reflex is to put your hand in front of your face to block this glare and somehow manage to see.
In layman language, glare is a light disturbing our vision. The intensity of glaring light can be different.
In modern times where digitization is crawling up to the peak, we do not even realize how constantly we are surrounded by artificial lights. Eyes are consciously or subconsciously subjected to mobile lights, computers screen lights, LED lights, blazing billboards, lights from vehicles, flaring sunlight, and many more.
Light travels in straight rays from its origin and whether it will be absorbed, reflected, or refracted depends upon the medium or surface it hits upon.
The heat or energy of light when gets absorbed by the atoms of a surface, it does not bounce back or travel to another medium. This is how light is absorbed. Such mediums can be soil, wood, or plants.
While Glass, cloth, or acrylics allows the light to pass through its surface. The angle of incident rays changes in the next medium. Surfaces like mirrors, water or snow reflect or throws back the light at the same angle. This may cause dispersion of light.
Unlike the natural source of light like the Sun, artificial light does not carry any vitamins with it. Even from Sun, only the morning hours are good to benefit from Vitamin D. Artificial lights can cause glaring depending on the intensity from its source.
Glaring is classified on basis of its source and effects on human body. Here is a rundown.
Distracting Glare
Distracting glare is medium intensity rays. Often you see a reflection on the back side of your lens which we also call the ghost effect is said to be distracting glare. It tends to draw your attention to the corner of your eyes causing distraction. Although, this glare can also occur on the front surface of your ophthalmic lens.
Lenses without ARC coating reflect light. 100% transmission is not achieved. As a result the person looking at your face will see white patch on your lens not making your eyes visible. Hence the solution is simple. Getting an anti-reflective coating on both the surface of your lens should sort you out.
The point to remember here is anti-reflective coatings do not cut the glare they allow more light transmission hence increasing the sharpness of the vision which in turn reduces effect of glaring.
Discomfort Glare
Your brain smartly ignores constant background noise when you wish to focus. Doing same thing sitting under flickering light is not possible for anyone. If your eyes are experiencing a change of light frequently it will cause a feeling of discomfort. Changing or turning off the light will relieve you from discomfort of flickering.
You must have experienced difficulty looking at something in your phone under bright sunlight. Despite your screen light you need to move away from sunlight to be able to check your phone. This kind of glaring light is discomforting glare.
Discomforting glares can be tackled easily with ARC-coated lenses or using photochromatic lenses.
Disabling Glare
The glare that affects the contrast of your vision which in turn disables you from viewing the image is called Disabling glare. This happens when the intensity of the light is very high. Due to such intensity, your eyes can experience squint, fatigue, or decrease in contrast.
To prevent this glare from disabling your vision you can use dark tint lens with an anti-reflective coating. Mirror coats have a shining outer surface that reflects light back. These can also be used in sunglasses. Although polarized lenses are efficient in providing ultimate relief when it comes to sunglasses. UV based lenses or filters are also effective in blocking disabling glare.
Blinding Glare
Light-reflecting from a smooth and shiny surface like snow, water or sand is very intense. If eyes are exposed to this kind of light it can cause potential damage to your vision.
Person may face difficulty in judging color or may experience squinting for small period of time and in the worst cases can develop a condition of Photokeratitis also known as Snow blindness which can be cured but remains for some months.
Blinding glare experienced while driving can be threat to life.
Polarized lenses with ARC or amber color lenses can save your eyes from disabling glare.
Final words
Glaring can also affect the contrast sensitivity of your eyes. Contrast sensitivity refers to your ability to differentiate between two close colors without borders parting them. Apart from glaring there are other factors that reduce the contrast sensitivity of your eyes. Some of medical conditions like Glaucoma, Cataract, Macular degeneration or side effect of medication can also reduce the contrast sensitivity. What most people do not know is that Lasik Surgeries also greatly affects the contrast sensitivity of your eyes.
If you wish to check the contrast sensitivity of your eyes you can take this test by Essilor. Click the link below.
