Can a tonometer actually touch you're eye ball?

Yes: There are many types of devices to check eye pressure. Many do touch the eye. However, the technician will place a numbing eye drop before touching the eye. You will feel light pressure while the instrument is touching, but no pain. Most patients describe it as a "weird" or "interesting" sensation. Be well.

For accuracy: The standard tonometer with the blue light used by the ophthalmoscope touches the anesthetized eye as does the handheld type. There is a less accurate one called air-puff used mainly by optometrists. The touch is extremely gentle and cannot harm the eye, even if you were to try. Be happy with the accuracy of this important measurement.