Well, in my opinion, there is something to do with contacts. As we know that, if you wear a pair of contacts which have wrong prescriptions, it will be easy to have the eye strain. And, you should know that eye strain can make your eyes feel stressed and heavy. Generally speaking, in some cases, it can put stress on the eye muscles and the facial and scalp muscles, causing pain and headache. And what is worse, it can lead to making your vision become worse. So you should wear the suitable contacts. Besides, there are also some other factors. So just do something to heal it and prevent it. For example, you should know that eye strain is actually the strain of the muscles controlling the eyes. Strengthening these muscles with a series of eye exercises will be a good way. And also you can drop some eye drops on your eyes. Besides, controlling the time you use eyes and the good position and lighting are also essential.
According to what you said, I can see that you have never worn contact lenses before right? So, actually, some people will not be accustomed to wearing contacts in the first place, and you are one of them and you had some uncomfortable feelings. So, generally speaking, it takes about several days before you are fully used to them. Should it do not turn out right, you should consult a doctor.