How to stabilize or improve my eye sight by any means except...?

... for Lasik surgery(not 18 yet) any other way of not worsening my sight because i have noticed that previously clear things (little writings on board) blur a little. i am wearing gles for about a year now , i don't want to buy new gles as my eye sight worsens because it is kind of expensive and lenghtly process... how to either improve or stabilize my sight?