The Midrash derives from this pasuk that everyone is “blind” until Hashem ultimately “opens their eyes.” This means that Hashem did not suddenly create a new well or transfer it from another place. It was present the entire time that Hagar was there, but she was not “permitted” to see it until Hashem “opened her eyes.”
The Sfas Emes cites his grandfather, the Chidushei Ha’Rim, who asserts that everyone’s truly essential needs are provided for him. Indeed, the fulfillment of his needs is within the grasp of each individual, but he does not have the ability to recognize this reality until Hashem raises the curtain from his vision.
In his anxiety an individual may wonder “from whence will come my salvation?” When he does not receive an answer to his request, he blames it on everything but the real problem– himself. Every attempt to solve his problem is futile. He stumbles as a blind person groping in the dark. The solution/salvation is right before his eyes. He must entreat Hashem to let him see, since “my salvation comes from Hashem.”