Follow these simple steps;
-Go to the configuration files location.
(%USERPROFILE%\Documents\My Games\GRID (2019)\hardwaresettings\hardware_settings_config.xml)
-Open hardwaresettings/hardware_settings_config.xml with a notepad.
-Search for depthOfField=”true” and change it from true to false.
-Save and set file to Read-only, failing to-do so can overwrite the previous steps if settings are changed in-game.