It has been known for a long time that similar to the cornea the conjunctiva possesses less discrimination between various Stimuli than the skin. According to v. Frey and Strughold (1926) only touch and pain sensations can be elicited from the cornea; the conjunctiva has in addition a sensation for cold which we shall, however, not consider in this monograph. Previous authors (v. Frey and Strughold, 1926; Boberg-Ans, 1955; Norn, 1973) agreed that the threshold for touch sensation is in the conjunctiva considerably higher than in the cornea. The authors also agreed that there are regional differences. Especially in the horizontal meridian the differences in the thresholds may reach 100–200%; the higher thresholds are found close to the limbus; the lower ones in the nasal or temporal periphery (v. Frey and Strughold, 1926). Norn (1973) did not examine many conjunctival points, but his results also reflect a certain regional variability in the thresholds. The various authors, however, found different absolute values for these thresholds which probably is due to the variety of examination methods used (compare also Norn, 1976). v. Frey and Strughold (1926) found that the threshold of the conjunctiva (30 g/mm2) was 150 times higher than the threshold of the cornea (0.2 g/mm2), whereas Norn (1976) found that the conjunctival threshold (8.48 g/mm2) was only 8 times higher than that of the cornea (1.06 g/mm2).