The movement of either eye into an up/right, up/left, down/right, down/left, up, down, right, or left position of gaze involves the linked and associated contractions and relaxations of multiple eye muscles, of the same eye and of the opposite eye, at the same time.ith the left eye looking to the right, if the IO muscle also were to contract, the front of this eye would move upward as well. Both eyes then would be looking up and to the right. This yoked or conjugate movement of these two muscles, right SR and left IO, is depicted in the first (top/left) image of the chart above.
Phytatesâwhich are present in whole-grain breads, cereals, legumes, and other foodsâbind zinc and inhibit its absorption [ 2, 12, 13 ]. Thus, the bioavailability of zinc from grains and plant foods is lower than that from animal foods, although many grain-and plant-based foods are still good sources of zinc [ 2 ].
Heme iron is most easily absorbed, whereas non-heme is absorbed less well. Calcium is the only known substance that can impair the absorption of both heme and non-heme iron. Tannin (coffee, tea, chocolate), fiber, eggs and oxalates impair absorption of non-heme iron. Red meat contains the most easily absorbable formof iron called heme iron. Fats (lipids) when in combination with unbound iron can generate free radical activity, which is destructive to cells and can damage DNA. Sugar enhances the absorption of iron. These beverages contain tannins which inhibit the absorption of non-heme iron. Excessive consumption of tannins is not recommended for individuals with liver damage. These foods are high in fiber, which impairs the absorptionof non-heme iron and promote healthy digestion. Shellfish can contain a bacterium called Vibrio vulnificus, which can be fatal to people with high body iron levels. Take care when walking barefoot on beaches where contaminated shells may be present.