> I found that my brain has a lot more computing power after I changed my scratchy old yellowed glasses to new ones. The mental filtering isn't free. I go thro

> I found that my brain has a lot more computing power after I changed my scratchy old yellowed glasses to new ones. The mental filtering isn't free. I go through this daily. If I notice I'm getting a headache-like eye pain, it's sign that my glasses have been slightly smudged for a period of time.