A recent survey of randomly selected users of disposable contact lenses found that more than 20% of people flush their contact lenses down the toilet or washed them down the sink instead of placing them in the garbage. Contact lenses are flexible and often fold up and pass through filters in waste-water treatment plants. The contacts absorb chemicals in the water, pass through to surface water, and can be ingested by wildlife. The survey suggests disposable contact lenses which are usually made up of a combination of poly(methylmethacrylate), silicones and fluoropolymers are likely a significant source of plastic pollution in waterways. Researchers suggest that companies add recommendations on contact lens packaging stating that the contacts should be placed in the garbage and not flushed or washed down the sink.