Is it okay to get tired eyes, feel tired and get a headache when you're hungry?

These go together. If you are suffering from all these symptoms at the same time, you are likely not taking in enough calories. When the body does not get enough nutrients and water, the eyes feel dry and/or tired, the relative drop in body water causes headaches, and the body tries to conserve energy by making you sleep. You should probably reassess the amount of calories that you are taking in.
Yes. A healthy snack and some rest sound like they are in order. People who have severe low blood sugar reactions sometimes report fairly dramatic changes in vision (e.g. Blurring, missing spots in vision). If this is happening to you, please see your primary care doctor for consideration of whether you are having blood sugar issues that should be assessed.