Hello As your age is 26 years so your power will not increase Using mobile from a close distance may cause headache and eye strain etc

Near work is an undisputed cause of myopic progression, whether it is smart phone or books. Always keep the smart phone as far away from you as possible while you can still comfortably read. The other commonly seen problem with excessive smart phone use is dry eyes/ computer vision syndrome, for which  conscious frequent blinking should reduce symptoms.

It will certainly cause eye strain even if the power may not change as you are already 26