Doctors encourage patients to become more active with regard to their health care. They know that engaged patients are more likely to have better treatment outcomes. The Internet, smart phones, and apps now provide patients with unprecedented access to health care tools, including home eye tests and other do-it-yourself diagnostic exams. This technology may help patients feel more confident about seeking early treatment, but ophthalmologists and optometrists know that home eye tests and apps can provide misleading results. The key message for patients is that an online eye examination is not a substitute for seeing a doctor who can detect much more than poor vision. Eye doctors frequently catch other illnesses, and detect chronic conditions such as diabetes and high blood pressure.