I had reading glasses of number 1; now i got my eyes tested again; dr. recommended 1.25; it changes over time?

Gradually: As you enter the 40's (presbyopia) your lens hardens and near vision needs help. The general range is +0.75 to +3.00 for corrective needs as you age in this sequence. When you reach the low 50's, the lens is like a rock and will not change after that so there is a top corrective need. The difference between +1.00 and +1.25 is small and you may not need such a small change if you read ok.