Contact lenses are useless without solution (just try putting them in after rinsing with tap water or even bottled water, or wearing unclean contact lenses for any length of time), so the solution is an essential accessory to the medical device. Unless you're arguing that contact lenses are not medical devices?

Compare it to the dangerous lithium battery in a pacemaker or the dangerously sharp needles for injecting insulin. Contact lens wearers won't have heart attacks or sugar-related discomfort without solution, but we'll certainly be extremely uncomfortable. What with the infected eyes and the bruises from walking into everything.