New Connecting Kids to Coverage Outreach Video. Learn about Las Vegas, Nevada's Foundation for Positively Kids outreach efforts using their network of community-based, school-based, and specialty health care clinics.
Young adults with 20/20 vision can often focus at 4 to 6 inches. At 6 inches, they can see detail at 600 pixels per inch or 300 line pairs per inch. As you age, your lenses become less resilient and the focus distance increases. At about 50 years, the average minimum focus distance is about a foot corresponding to 150 line pairs per inch or 300 pixels per inch. These numbers reflect good light and high contrast scenes. Generally, under more typical conditions, people don't see this well. --.
The normal sight is 20/20. The first number is the distance (20 feet) from the eye chart. The second number is the distance from which a normal eye sees a letter on the chart clearly. Someone with a visual acuity of 20/20 can see certain sized letters at a distance of 20 feet. Someone with a visual acuity of 20/40 only sees letters at 20 feet that a normal eye is able to see at 40 feet.