Does The Physical Or Mental Impairment Of A Party Make An Arbitration Agreement Voidable?

For an arbitration agreement to be enforceable, the parties must have a reasonable opportunity to understand its terms. See Fagerstrom v. Amazon.com, Inc., 141 F. Supp. 3d 1070 (S.D. Cal. 2015). With this principle in mind, the U.S. Court of Appeals for the Ninth Circuit commented in 2006, regarding the enforceability of an arbitration clause that was prominent in a contract, "You'd have to be blind to miss this warning. There was no surprise here." Nagrampa v. MailCoups, Inc., 469 F.3d 1257, 1309-10 (9th Cir. 2006) (en banc) (emphasis added). But what if the plaintiff in Nagrampa had been blind, or was otherwise unable reasonably to read, or to understand, or to appreciate the significance of the arbitration clause by virtue of a disability or a more temporary impairment?