Thank you for posting your query at DoctorSpring.com
I understand your concern.
I have gine through your history diligently. It does not seem like a heart issue or a seizure. In some people this can happen momentarily lasting for about 4-5 seconds where there is a slight disturbance in the electrical activity in the brain. It is an incidental finding in most normal cases. Moreover working in the IPAD for a long period of time could have also led to fatigue leading to what happened to you. During such focal disturbances the eyes seem like crossing and at times the images in front will move around. In your case since it is lasting for only 2-3 seconds, there is absolutely no reason to be worried. For that matter even fatigue can lead to such manifestations. In both cases you were using your ipad, if you were working for quite a long time, the eyes can go for fatigue and similar episodes can occur.
Did you have any feeling of loss of conciousness at that moment? Did you have any nausea/vomiting?
In my opinion, there is nothing to worry about. Since you're already prone for anxiety, i can assure you it is nothing related to your heart or brain.
If it keeps happening too frequently, then a CT SCAN will be advisable. But as of now there is no need for any investigation. I will advise you not to use IPAD continuously and take adequate breaks in between.
Hope this was helpful,