Small white dots appear on MacBook Pro display

As I have been using my mac regularly for the past 3 years & all of sudden I noticed a certain small white patch appears on my display.

first I thought that was due to dust but after certainly failed attempts of removing it the problem is still there and after a few days I notice there has been increasing in the patch and had started spreading.

for reference, I have attached certain photos of the patch.

It's had to find in other colours but bright visible in white background.

[Re-Titled by Moderator]