the pinhole eye is an advanced form of pit eye. it has several bits, most notably a small aperture and deep pit. sometimes, the aperture can be changed. it is only found in the "nautilus". without a lens to focus the image, it produces a blurry image. consequently, nautiloids can not discriminate between objects with a separation of less than 11°. shrinking the aperture would produce a sharper image, but let in less light.