One thing that hasn't been mentioned is eye dryness. When we sew, read, or do anything that requires concentration, we don't blink as much as normal. Longer periods of time between blinking causes the natural tears to dry and vision to become blurry. I have a bottle of artificial tears by my computer, sewing machine, bedside, in the truck....etc to use whenever my eyes get dry. When severely dry my eye doctor suggested placing 2 drops in each eye every hour. This simple suggestion has helped tremendously and I can thread a needle in my machine without asking for help. Any preservative free eye drop for contact use will work but please don't use the Visine type drops, those cause a whole nother set of issues.