 By understanding this better, the mechanism of drug loading and the controlled and sustained release of drugs to a patient's eye can be optimized.Since contact lenses are used on a part of the body that is important for normal daily functioning (sight) it is critical that scientists take into account the transparency of the lens.As larger and more drugs/objects are loaded to a contact lens it begins to physically crowd the space available, making it more difficult for light to penetrate and reach the eye.