Refractive error was a high possibility but your optician would have checked your precription. However, there could still be an error and I would advise you to see one more optometrist. Another possibility is convergence insufficiency. Get that also checked by the optometrist. If you sit on computer for too long then you could be having dryness in your eyes as well. I would advise you to use a lubricating eye drop like Refresh Tears 3 times a day.
Yes, it needs to be checked. Convergence insuffiency is still a posssibility though problems in doing near work like reading are more common. Refractive error should also be rechecked. If both turn out to be negative then go for an orthoptic check-up as well. Thanks.