Is exposure to computer screens, which has weakened eyesight, considered casting oneself into destruction, which is forbidden in His — the Almighty’s — saying: "And do not throw [yourselves] with your [own] hands into destruction"?

It is not permissible to neglect the eyes and expose them to harm, because the Sharia has forbidden all types of harm and injury, based on the Prophet's (peace be upon him) saying: "There should be neither harming nor reciprocating harm."

Therefore, one must follow the doctor's advice when using a computer, and observe the means that do not harm the eyes. One should seek forgiveness for past negligence and not be negligent regarding health, because it is one of God's blessings that must be preserved. If the harm persists after taking precautions, then there is no blame in that, and the patient will be rewarded.