The prob is not in your spectacles. See people working for long hours on computer generally suffer from computer vision syndrome (CVS. Your symptoms are due to this.
1st of all have a healthy balanced diet and proper hydration.
2nd try to avoid working continously for more then 2 hour. Close your eyes or take a break.
3rd Use eye drop cmc
tear or tear drop) 4 times a day.
4rth Normally computer come with antiglare and protection screen. But you can try on your specs too.
5th Proper walk for 15 min a day and pencil
pushup exercise for 10 min.
And regularly have your refractive error checked around 6 mnths.
Try to follow up after 15 days.