LibGDX's problem, sprite and MouseMove uses different coordinate system, and requires transformation before use.

Iris.java

	@Override
	public boolean mouseMoved(int screenX, int screenY) {

		screenY -= Gdx.graphics.getHeight();
		screenY = -screenY;

		double length = Math.sqrt(Math.pow(((double)(screenX - sprite.getX())), 2d) + Math.pow((double)(screenY - sprite.getY()), 2d));
		sprite.translate((float)((screenX - sprite.getX()) / length), (float)((screenY - sprite.getY()) / length));

		System.out.println("Screen : " + screenX + "/" + screenY);
		System.out.println("Sprite : " + sprite.getX() + "/" + sprite.getY());


		return false;
	}