Camera become blur after drop in water

@nano95 you did not tell us if you dealt with the water damage. Since it worked first but now does not work properly, it stands to reason that it is either starting to show signs from the water damage or that your phone is starting to fail due to corrosion etc.

If you have not dealt with the water damage then you do want to look at it now. Disassemble your phone using this teardown Samsung J7 Pro Teardown Video Only and clean everything after you remove all the EMI shields from your circuit board. If you do not remove those you are not cleaning 3/4 of the board.

Clean everything with +90% (no less than 90%) isopropyl alcohol. Follow this guide, and even so it was written for an Apple iPhone 3G all the points are still pertinent to your phone. Pay particular attention to the SMD components, check for charred missing or broken missing. You can then dry the board in an oven or equivalent at 220deg F (not higher;-) for a few hours. Best way to clean it would of course be through an ultrasonic cleaner. Consider professional help with that When it is properly cleaned, replace the battery. All these steps are to avoid delayed failure caused by corrosion. Once all this is done, reassemble your phone and reevaluate. It is possible that it is "only" the camera that has failed, but you can only determine that once you cleaned the phone properly.

As always, if not sure what you are looking at or if you are unsure if your board shows corrosion or missing, damaged part, post some pictures with our question. For that use this guide iFixitでの質問に画像を追加する方法