Don't flush your contacts down the toilet. Instead, chuck them in your regular waste bin. The artificial materials that contact lenses are made of - hydrogel and silicone-hydrogel - are not biodegradable, which means that they fall apart into tiny pieces, but are not decomposed by living organisms and therefore constitute a threat to water systems and animals who live in them. People who flush contacts down the toilet contribute to water pollution, so please don't do it.
We recommend waste recycling whenever possible. Chuck lens and lens solution cardboard boxes into your paper container and solution bottles into the plastic one. Lens blister packs and lens cases can also be recycled as they are made of polypropylene. Take care of your environment according to regulations in your region.