So much more than a refraction goes into an eye exam. A comprehensive exam includes the assessment of the eye health, and can help diagnose and monitor systemic disease. The conditions include, but aren’t limited to, diabetes, high blood pressure, rheumatoid arthritis , elevated cholesterol, multiple sclerosis, stroke, brain tumors, brain aneurysms, and metastatic cancers. The device you mention that can determine the refractive status of the eye is known as an auto refractor and has been around since the mid 80's. New versions have incorporated wave front analysis which is the same technology that the Hubble telescope utilizes, yet it still can’t provide an accurate subjective refraction. You see, each individual receives and processes visual information differently. This is why the doctor still asks specific sequence of questions which you find unnecessary. Both eyes must be balanced together to determine their best binocular prescription. For now, there are no algorithms or objective testing that can determine this. While your vision of the eye are industry will use some meaningful method of determining the prescription via a smart phones,there are professors and doctors specifically trained in Optometry who know this is impossible. As for now, be thankful that there are people who are dedicated to train for eight years to determine your eyeglass prescription. Perhaps you can now better appreciate their dedication to your visual needs and realize they aren’t wasting your precious time.