From the U.S. Bureau of Labor Statistics...
"Optometrists are doctors who focus on eyes and vision. Their tasks range from offering preventive care through routine checkups to providing referrals to other specialists for treatment of health conditions, such as autoimmune diseases, that may lead to serious eye problems.
Some optometrists provide specialized care in addition to general eye care. For example, some optometrists focus on treating patients who have partial sight, a condition known as low vision. Others may specialize in treating a certain population, such as infants and children.
Optometrists promote eye health by counseling patients on how general health can affect eyesight. For example, they may counsel patients on how quitting smoking lowers the risk of developing cataracts."