Are there references to or descriptions of the Buddha’s eyes in the Pali or Chinese canons?
Aṭṭhisutta SN 19.1
“Just now, reverend, as I was descending from Vulture’s Peak Mountain I saw a skeleton flying through the air. “Idhāhaṁ, āvuso, gijjhakūṭā pabbatā orohanto addasaṁ aṭṭhikasaṅkhalikaṁ vehāsaṁ gacchantiṁ.
Vultures, crows, and hawks kept chasing it, pecking, clawing, and stabbing it in the ribs Tamenaṁ gijjhāpi kākāpi kulalāpi anupatitvā anupatitvā phāsuḷantarikāhi vitudenti vitacchenti virājenti. as it screeched in pain. Sā sudaṁ aṭṭassaraṁ karoti.
It occurred to me: Tassa mayhaṁ, āvuso, etadahosi: ‘Oh, how incredible, how amazing! ‘acchariyaṁ vata bho, abbhutaṁ vata bho. That there can be such a sentient being, Evarūpopi nāma satto bhavissati. such an entity, Evarūpopi nāma yakkho bhavissati. such an incarnation!’” Evarūpopi nāma attabhāvapaṭilābho bhavissatī’”ti.
Then the Buddha said to the mendicants: Atha kho bhagavā bhikkhū āmantesi:
Mendicants, there are disciples who live full of vision and knowledge, “cakkhubhūtā vata, bhikkhave, sāvakā viharanti; since a disciple knows, sees, and witnesses such a thing. ñāṇabhūtā vata, bhikkhave, sāvakā viharanti, yatra hi nāma sāvako evarūpaṁ ñassati vā dakkhati vā sakkhiṁ vā karissati.
Formerly, I too saw that being, but I did not speak of it. Pubbeva me so, bhikkhave, satto diṭṭho ahosi, api cāhaṁ na byākāsiṁ. For if I had spoken of it others would not have believed me, Ahañcetaṁ byākareyyaṁ, pare ca me na saddaheyyuṁ. which would be for their lasting harm and suffering. Ye me na saddaheyyuṁ, tesaṁ taṁ assa dīgharattaṁ ahitāya dukkhāya.
That being used to be a cattle butcher right here in Rājagaha. Eso, bhikkhave, satto imasmiṁyeva rājagahe goghātako ahosi. As a result of that deed he burned in hell for many years, many hundreds, many thousands, many hundreds of thousands of years.
Now he experiences the residual result of that deed in such an incarnation.” So tassa kammassa vipākena bahūni vassāni bahūni vassasatāni bahūni vassasahassāni bahūni vassasatasahassāni niraye paccitvā tasseva kammassa vipākāvasesena evarūpaṁ attabhāvapaṭilābhaṁ paṭisaṁvedayatī”ti.
If you mean the Buddha’s “five eyes”, as opposed to just the eye of flesh, there are individual mentions of these scattered throughout the suttas, but the Niddesa to the Sn’s Mogharājamāṇavapucchā is the earliest text to collate and define them all.
If you just mean the eye of flesh, the same text has quite a bit to say about this too.
If you don’t know Pali, Google’s translation of the Sinhala translation will give you the gist of it.