The difference between ARC and Blue Block
Sumayya Vanker - B.Optom (UDW)
Our eyes are bombarded daily by glare and reflections from computers, tablets, cellphones and artificial light such as LED, fluorescent lights, and car headlights, for most of the day and evening causing eye fatigue and headaches.
Anti-Reflective Coatings (ARC) and Blue Block on spectacle lenses help to reduce the effects of glare by reducing eyestrain, enhancing visual clarity and comfort, and improving the aesthetic appearance of your spectacles.
So, what is the difference between ARC and Blue Block?
ARC is a thin, multi-layered film applied to the front surface and back surface of spectacle lenses which reduce visible reflections by 80-90% depending on the quality and layers of coating. It is mostly transparent with a shimmer of green/purple when viewed at an angle. Most ARC are scratch resistant, water repellent, dust and dirt repellent and have anti-static properties. Visual benefits include sharper vision and greater comfort when driving at night and using screens for prolonged periods of time. It is highly recommended for high index lenses (thinned down lenses) as these lenses cause up to 50% more glare due to the materials used to make the lens. Aesthetically, ARC aids in people being able see your eyes by eliminating the glare from your lenses which improves communication with others as well as making your eyes clearly visible in photographs and video calls/meetings.
Blue Block is a blue light filter which is available as an inclusion to ARC
above, or, infused in the monomer (material) of a spectacle lens. Blue light is High Energy Visible (HEV) light
as it is very high on the visible light spectrum, just before UV light. Prolonged exposure to blue light from digital
devices and the sun can cause eyestrain, dry eyes, cataracts, macular degeneration
and reduce the secretion of melatonin, a hormone necessary to regulate our
circadian rhythms (sleep cycles). Blue block
filters up to 90% of HEV thus reducing the harmful effects above. It is highly
recommended for all users of digital devices except for people whose work
involves colour shading or differentiation such as graphic designers, artists,
photographers, etc as the blue filter causes colour distortion in certain
colours such as the colour white.
Aesthetically, the blue block coating has a noticeable flash of blue at
certain angles whereas the infused blue block causes the lenses to appear to
have a slight yellowish tint.
Your spectacle prescription, occupation, lifestyle and hobbies all contribute to whether a standard ARC or Blue Block will be suitable for you, so it is advisable to discuss this further with your optometrist and/or optical dispenser for guidance on selecting the most suitable coating for your needs.