There are several classifications of contact lenses and same goes for colored contact lenses. Classification may be through function, material and many others. Let's focus on function for now. If you want to know more about this, check out Colored contact lenses.
CORRECTIVE This type of color contacts is used to improve vision. The corrective functions by allowing light to properly enter the eye with the correct power and clearer vision. It bends the light horizontally or vertically to properly distribute the light that enters the eye. It is also the corrective lenses that corrects and prevents astigmatism. With astigmatism a toric lens must be used.
Other deficiencies in vision for correction are color deficiencies and red-tinted or X-Chrom.
COSMETIC CONTACT LENSES The main purpose of a cosmetic eye is to change the appearance of the eye completely. There are cosmetic contact lenses that come in different colors. Thus, these type of lenses are also called colored contact lenses. The FDA also considers this type of contact lenses as non-prescription.
Cosmetic lenses are more often used by celebrities and theatre performers to depict more emotions. In fact, there are cosmetic contact lenses which were custom made for a specific production and are not available for public purchase.
There are also cosmetic contact lenses which have grade for vision correction purposes.
In some countries like Japan, Korea and China, there are cosmetic contact lenses that come in different colors and are used for cosmo play. The colored contact lenses make the cornea appear bigger and wider. Functional colored contact lenses are used to replace missing iris. For more info, visitthis URL.