Hi Latent squint can manifest in times of stress and cause asthenopic symptoms such as head ache and brow pain. I mean to say that ,whenever there are certain factors of stress such as prolonged reading or excessive use of screen , eye can get squinted and you feel head ache because eye has to work hard to send a single image to brain ( usually people with gross squint see two images) . If you had undergone a refraction test in the previous 6 months,no  need to worry now and you can take carboxymethylcellulose drops One drop three times per day in both eyes  and you will be be fine otherwise, you need to get your vision Re tested.