Either eyes means something else in New Zealandian, or this dude is having a major brain fart.

"Why aren't they spelled 'I-s?'"

Jeanette Manu asked her fiancé Don what E-Y-E-S spells. For some reason, the synapses in his brain that help him spell the word "eyes" weren't firing. He was dumbfounded. He spelled it out for her, and concluded that it spelled e-yes, as in e (rhymes with see) - yes (rhymes with less). She kept asking him and he kept telling her, "E-YES!" between laughter and frustration. Finally, in a divine act of mercy, she tells him off the hook and tells him that it spells "eyes." He pauses for a moment and then bursts into laughter, telling her to "fuck off" like a true Kiwi.*

*Apparently New Zealanders are called Kiwis. It's not offensive or anything, it's just like a nickname. You learn something new everyday. 

Sources: YouTube/Jeanette Manu