Yes, it is normal. And you will get recovery soon. After donating the blood, you will find that your body is so weak. Your eyes may lack of water. You will feel the headache because of the weak constitution. You'd better have the good rest for the body and the eyes. At the same time, you could also have the nutritious food to intake.
Well, yes, it is possible to have blurry vision after you have donated blood. First, the symptoms you are experiencing may be related to a temporary decrease in serum calcium levels. And because of this reason, it is possible to affect your eyes, leading to blurry vision. But on the other hand, you should know that it can recover after a while. Also, you can just take some milk and have a rest. So that it can be fine.
Yes, it is quite possible to happen. According the resources, many people might have some uncomfortable feelings after blood donation, but actually reaction to blood donation is rare. About 2% of donors have adverse reaction to donation, and most of them are very minor. And some of them are have reaction due to the rapidly decreased blood pressure, which is referred as Hypovolemia. Symptoms of hypovolemia include fainting, rapid breathing or heart beating, coldness and paleness of skin. Some people have adverse reaction because of the sodium citrate used to keep blood from clotting. It is called hypercalcemia. Direct impact on eyes or visions is very rare. Based on your description, it is probably related to the two situation stated above. Yet you don't have to worry too much. These symptoms usually go away very quickly. After donation, you should drink a lot of warm water, and milk. Have a good rest is important too. There are many people around the world are encouraged to donate blood, and there is very rare of cases that donators have any long-term complications as long as if the equipment uses is clean and sterilized. So, don't worry, you will recover very soon.