1. A lens evaluation method, comprising the steps of: irradiating an image light including a resolution-measuring test pattern onto a screen through a lens to display an image of the resolution-measuring test pattern on the screen; detecting a luminance of the image of the displayed test pattern by an image import device using an image sensor, a resolution evaluation value being calculated based on the detected luminance value; acquiring a background luminance value of a background part without the test pattern being formed by the image import device using the image sensor; acquiring a maximum luminance value in the test pattern image by the image import device using the image sensor; acquiring a minimum luminance value in the test pattern image by the image import device using the image sensor; and calculating the resolution evaluation value based on the background luminance value, the maximum luminance value and the minimum luminance value obtained through the respective steps.