Accessing the window from Angular expression

According to the developer guide I should be able to access the browser window from inside Angular expressions with `$window`. Unlike JavaScript, where names default to global window properties, Angular expressions have to use $window to refer to the global window object. For example, if you want to call alert(), which is defined on window, in an expression you must use $window.alert(). However I can't seem to access `$window` from expressions evaluated with `$scope.$eval`. Here are some outputs I get when logging out to the console: ``` console.log($window); // the Window object as expected console.log($scope.$eval('$window')); // undefined console.log($scope.$eval('1+1')); // 2 console.log($scope.$eval('scopeVar')); // 'abc' ``` The controller has `$window` as a dependency. I can access scope variables and other services from expressions but not `$window`, so `$scope.$eval($window.alert())` doesn't work either. What am I missing here?