Blocked tear duct, which is characterized by a lot of tearing.

These soft contact lenses are worn every day for six months up to one year. They require daily cleaning and disinfecting, as well as a periodic enzymatic soak (usually once a week).

Corneal layer between the stroma and the endothelium.

Leaking of retinal blood vessels in advanced or long-term diabetes, affecting the macula or retina. Vision can be seriously distorted or blurred.

Unit which measures the refractive (light-bending) power of a lens; eyecare practitioners use it in eyeglass and contact lens prescriptions. A negative number refers to nearsightedness, while a positive number refers to farsightedness. For ex

Technically, this is any contact lens that is thrown away after a short period of time. Among most eyecare practitioners, "disposable" usage ranges from one day to two weeks, while "frequent replacement" lenses are discarded

Also called ptosis. Condition in which the upper eyelid(s) only sag. It can be present at birth or caused by a later problem with the muscles lifting the eyelid, called levators.

Lack of sufficient lubrication and moisture in the eye. Most dry eye complaints are temporary and easily relieved; dry eye syndrome is chronic and needs more advanced treatment by an eyecare practitioner.