As Bill said...could be your eyes.
#1. How is your hold and trigger pull? If these are not good or at least decent, you need to work on these.
#2. What color/shade is the target and paper. If you don't have enough light on the target, the front sight won't have enough contrast to be easily seen.
#3. Can you easily FOCUS on the FRONT sight. I my case, I could not. If you can't focus on the front sight, you can't aim well. I had to have a glasses made so I could focus on the front sight, and still see the target.
#4. What is the ratio of the visible width of the light on both sides of the front sight blade compared to the front sight. The 2 standard for target shooting are 1:2:1 and 1:1:1.