There’s another way to see better than just cleaning your glasses when they’re dirty, suggest optometrists at the University of Houston College of Optometry. We can apply their no-cost, at-home approach, called pencil push-up therapy.

The simple exercise, when practiced regularly, the doctors say, can improve visual acuity and performance at school and work. How does it work? Visually follow a small letter penned or pasted on a pencil eraser as you move the pencil closer to the nose. The goal is to be able to keep the letter in focus until it touches the nose.

The exercise appears to help with a common condition known as convergence insufficiency, which may affect up to 20 percent of the population. The condition refers to someone who can’t cross their eyes. If left unattended, it can affect their reading skills and cause headaches and eye strain. In-office professional vision therapy also can help, but the do-it-yourself exercise works well.