By the time we are 40 we have already experienced Presbyopia, or “old eyes”. As we age the lens of our eye loses flexibility, and by 50 most of us need glasses and are holding the “small print” further and further from our eyes. The lens’ ability to change shape to accommodate to objects brought close to the eye is called “accommodation”. Indeed the ability to accommodate is a basic “biological age” test bio-marker.
Modern living exacerbates this age-related tendency to lose accommodation. The theory of evolution says that our eyes are designed for hunter-soldier vision based on a need to spot game and enemies at a distance. Only recently have the majority of us been occupied in sustained daily near vision tasks for year after year from a young age.
So the following 10 steps to visual hygiene are recommended to reduce the heightened visual stress this admittedly mostly unavoidable modern near vision predominance produces.
- Look up and away from near vision tasks often.
- Lighting illumination should be three times brighter than the rest of the room. DO NOT read under a single lamp. Eliminate all glare.
- Sit straight and have your work at eye task level.
- Best distance is 14 to 16 inches for adults.
- Avoid reclining postures. Sit up right while reading or watching TV in bed.
- Writing: Hold your pen at least one inch from the tip so you do not need to tilt your head to see your words as you write.
- TV: View at a distance at least 7 times the width of the TV screen.
- Participate in outdoor activities that require seeing at a distance.
- Eat a diet high in a wide variety of fruits and vegetables all the colours. Supplement with anti-oxidants and botanicals known to promote eye health like lutein, zeaxanthin and bilberry.
10a) Wear black-gray and green-gray because they allow the full spectrum of colors evenly without distortion.
10b) Blue is bad for it scatters light. Pink and yellow allow more light and strain the eyes on bright days. Cataracts sufferers should use brown for its softer tones. Polarized means a plastic film between the lenses that cuts off harmful glare and reflection.
10c) Most prescriptive sun glasses today have built in UV protection for both UVA and UVB which are the next two wavelengths after ultra violet on the visible spectrum. Check for the word filtered on the tag. Transitional lenses are clear indoor and dark outdoors, have a gray hue all the time, which is caused by UV from indoor fluorescent lighting.
10d) Best to wear at the computer and for night driving to reduce the halo effect are lenses with anti-reflection coatings that let in more light.Last modified: December 30, 2020