Contacts are plastic lenses that are placed directly onto the eye to improve vision. There are two main varieties: soft contact lenses, and hard rigid gas permeable (RGP) lenses. Most people use soft contacts as they are more comfortable and inexpensive, though hard RGP contacts are easier to manipulate with the fingers and get into the eye. Soft contacts have gotten so cheap that they are now available in disposable form and no longer require the extensive cleaning regimens of the past. Advanced toric contacts can now fix astigmatism and multifocal contacts can sometimes help with reading vision. Colored contacts have color pigment silk-screened on the plastic to change eye color – I don’t recommend these as they have a high rate of eye infection. The newer contact lens designs allow much more oxygen to permeate through the plastic and have been approved for extended wear so that you can sleep in them … I don’t necessarily recommend this either, as wearing contacts for extended periods dramatically increases the likelihood of infection, GPC, and corneal ulcers. Contact lenses are much harder to “fit” than glasses as they come in different steepness and diameters, thus contacts usually require a “fitting” for the first-time user and a refitting with any major prescription changes.