Eye exam (eyeglasses only) - $60. Contact Lens eye exam - $90 (includes eyeglass exam) Pupil dilation and visual fields costs extra. The eye exam costs are more likely to vary from store to store as the optometrist is not directly employed by Costco.
Colorado, as many other states, has determined the age of majority to be 18 years of age or older. Individuals are treated as adults at the age of 18, with some exceptions, such as drinking alcoholic beverages (12-47-901), renting cars, and purchasing a hotel room. When an individual reaches the age of majority his or her parents are no longer liable for their child's actions.
The drinking age is the only exception to the legal age of adulthood in the US. We consider 18 year-olds to be adult enough to vote, serve in the armed forces, enter into contracts, marry, and even serve on juries. Legal age 21 is inconsistent with our notion of what it means to be an adult in the United States.