https://devforum.roblox.com/t/how-do-i-get-the-exact-mouse-position/1618057/13
local mouse = player:GetMouse()
local function WhereIsMouse()
if (mouse.x / mouse.ViewSizeX) <= (mouse.x / mouse.ViewSizeX) then
print("mouse is on left side of screen")
else
print("mouse is on right side of screen")
end
end)
*untested