If a guys head hit my eye (from 12 to 24 inches away), and my eye is experiencing occasional pain that sometimes corresponds with movement, am i now at a bigger risk of getting glaucoma or retinal detachment in the future? my eye is also a bit itchy?

Hitting the area of an eye may or may not cause problems, depending on the amount of force. People with eye symptoms should see a doctor. In general, physical activity such as sports activities, does not lead to more glaucoma cases compared with the number of cases in the general population. Thus, athletes can do what the general population does... get eye check-ups yearly if their doctor says so.