With the lens removed, we can now take a closer look at the iris. Using a blunt probe, carefully separate the tissue of the iris from the rest of the eye. If you have trouble getting a good grip or working with the eye, you can use locking forceps or tweezers to hold the eye in place while you slowly pull the muscle tissue of the iris away. Looking at the removed iris, the pupil, as well as the muscle that surrounds it, should be clearly visible. Looking at the back half of the eye that we set aside earlier, we can now get a closer look at the retina. In a fresh cow eye, the retina can be extremely fragile and can shift during the dissection. Some of the retinal tissue on this eye has lost its original form, but the original blood vessel structure is still clearly visible. Since the condition of the retina at this point in the dissection can be variable between different eyes and different dissections, the blind spot and the fovea may not be clearly visible. Here the blind spot is the area of the retina tissue that stays attached to the wall of the eye, corresponding to the location of the optic nerve on the back.