Yes, the detached retina will cause the headaches. The detached retina is often happened among the people with high prescription. The strong knock may easily cause the detached retina. The brain and eye nerves are interlinked. That is why the headaches happen from the detached retina. You should let your friend go to the hospital to accept the treatment as soon as possible.
The retina is a very thin tissue which lies in the back of the eye. The nerve ends transmit the image in the form of electrical signals to the brain so that we can see what we see. Detached retina means retina peels away from the back of the eye. The initial symptonms of the detached retina or retina tear is flashing lights and floaters. And then it may progress to be dark curtain or shadow affects the vision. This is exact the signal that retina tear develops to retina detachment. It is hard to tell whether headache is caused by retina detachment or not. Eyetrains cause headache too. Anyway retina detachment is very seriour, your friend should go to the hospital at the earliest. Hope this helps.
Yes, as a matter of fact, there is really a connection between detached retina and headache. A detached retina can be caused by many reasons, such as strong prescription, a heavily violent collision or a pair of flimsy retina. Once the retina detach, the part where is detachment can not work, meanwhile, image and message the brain accepted from eyes is not complete or even total loss, eventually lead to the dysfunction of brain. Accordingly, it's quite normal to get a headache of your friend. The direct way for him is go to the hospital to get a physical examination and take a detached retina surgery as soon as possible.