[Terry_Roll]

I found having the brightness of the monitors turned helps alot, my monitor lux level is like 30 from 5cm away from the monitor. Plus as a kid I had glasses because the TV made my eyes water, the new LED light bulbs do the same thing as do some TV's.

Now a variety of chemicals are involved in eyesight, histidine has been shown to reduce or prevent cataracts building up in Salmon, vit K alters an enzyme which also reduces the calcium buildup in the eye, so I wonder if eyesight is purely down to diet and exercise?

[akemichan]

As far as I know, there's not much evidence that physical exercise can influence visual acuity on humans(other than reducing it due to general body fatigue), though I'd love to read more on that if someone happens to know of a study on the subject. Diet, on the other hand, may influence it. Generally speaking you can't consider a part of the body as if it were it's own isolated system: the general state of the body will influence them. To give a practical example, contraceptive pills change the tear composition making it hard for women taking them to use contact lenses.

Most of the issues related to lights/monitors, apart from the effects on the eye development due to prolonged near distance focus, are related to the quality of the tear film, not so much about the actual visual acuity or the refractive capacity of the eye. For example, the ambar-colored night mode that most OS have now not only decreases the brightness, which helps with visual fatigue, but also stimulates the production of melatonin, which is essential to enter "night mode" and make it easier to fall asleep, in contrast with blue lights, which reduces melatonin production and puts you on alert mode during the day.

In humans, cataract is mostly(not accounting for birth pathologies or trauma) caused because the crystalline, since we are born, never stops producing collagen, the substance it's mostly composed of. At late ages, the crystalline has produced so much collagen that it loses transparency, thus causing cataracts. It's also the same reason people develop presbyopia as they age: the collagen production reduces the crystalline elasticity, making it harder and harder for the eye to adjust it and focus on near distances.

[Terry_Roll]

K1 Enzyme I think I was thinking about. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6789135/

Salmon cataracts https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2709424/

>you can't consider a part of the body as if it were it's own isolated system True, we cant control where some chemicals go in the body, but this is where the pathways come into play or the other chemicals in a meal. For example, there is reportedly a gut receptor for copper or zinc which can take upto about 800mg a day, but copper and zinc are competing obviously. Other factors include say tea drinking, wear https://www.sciencedirect.com/topics/food-science/phytate inhibit copper, zinc and iron iirc.

So when thinking about say supplementing, sometimes the delivery mechanism or consumption format doesnt help.

Vitamin K1 doesnt appear to have an upper limit if taken orally, but inject it and you will get a reaction.

Its like a complex chemical maths puzzle, but by bit studies give us a range of info and its a case of piecing it all together. In some cases studies dont even exist!