Some of the most likely suspects to be causing something like this in a person who has had a retinal detachment repaired is either:
A. a vitreous (jelly in back of the eye) hemorrhage or vitreous floater obscuring the view: this would be accompanied by this "spot" where you're not seeing so well intermittently moving when you move your eyes but then catching back up to the previous spot.
B. This may be from swelling in the retina: when the center of the retina collects fluid it can cause symptoms like this.
Additionally, it is possible a cataract has started forming and is causing a focal area where you're not seeing very well.
Unfortunately, aside from knowing whether this spot moves with your eye movements or stays in the same place all the time, there isn't much more that we can do together to ferret this out because you need to have your eyes examined.
I would recommend that you make an appointment to see your ophthalmologist as soon as you are able.
Unlikely, but still possible, is that the retina is starting to detach again; this is unlikely because the vision overall would start to be significantly worse and not just be limited to a spot in the center of the vision.
Does this information help address your concerns? Does this make sense? Do you have any other concerns that I haven't addressed?
I am happy to be able to help you today. I will also be happy to answer any other questions until you have the information you need.
This does not end our conversation, however-we can continue to discuss any of your concerns without further charges until you are satisfied.
Any positive feedback and/or bonus you may feel prompted to provide would be welcomed and is appreciated. Thanks for your inquiry!
My opinion is solely informative and does not constitute a formal medical opinion or recommendation. For a formal medical opinion and/or recommendation you must see an eye doctor.