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 age one becomes a legal adult in the US is largely the age at which most children are considered adults in the world. A few countries set this age lower, but in most of the Western world, one is considered an adult at 18.