contact lens, n. — Green’s Dictionary of Slang

contact lens n.

[its hallucinatory effects + ? ref. to ‘making contact’ with one’s inner self]

(drugs) LSD.

1977		L. Young et al. Recreational Drugs.
1982		AS LVII:4 289: When LSD is mixed with other drugs [...] [s]uch mixtures are today called [...] contact lens.
2001		ONDCP Street Terms 6: Contact lens — LSD.