It is mostly irrelevant whether the perpetrator of a crime has one eye or two, because the verses Exodus 21:23-25 are referring to monetary penalties, except in the case of murder. Here is the text from Exodus 21:23-25, all three verses of which are important in understanding the answer to your question:
23: אִם אָסוֹן יׅהְיֶה וְנָתַתָּה נֶפֶשׁ תַּחַת נָפֶשׁ
24: עַין תַּחַת עַין שֵׁן תַּחַת שֵׁן יָד תַּחַת יָד רֶגֶל תַּחַת רָגֶל
25: כְּוִיָּה תַּחַת כְּוִיָּה פֶּצַע תַּחַת פָּצַע חַבּוּרָה תַּחַת חַבּוּרָה
23: But if there is a fatality, then you shall give a life for a life,
24: an eye for an eye, a tooth for a tooth, a foot for a foot,
25: a burn for a burn, a wound for a wound, a bruise for a bruise
As it turns out, only the phrase a "life for a life" was never carried out literally. And even in the case of murder, three witnesses were required for the Sanhedrin to issue a death sentence, which this was seldom done. In all other forms of injury, the text was treated figuratively, as an allusion to monetary compensation. The Talmud (Bava Kama 83b) states:
One who maims his fellow is indebted to him on account of five things: damage, pain, medical treatment, incapacitation, and shame. How so with "damage"? If he blinded his eye, amputated his hand, broke his hand, he is considered as if he was a slave sold in the market, and a valuation is made as to how much he was worth and how much he is worth.
החובל בחבירו חייב עליו משום חמשה דברים בנזק בצער בריפוי בשבת ובושת בנזק כיצד סימא את עינו קטע את ידו שיבר את רגלו רואין אותו כאילו הוא עבד נמכר בשוק ושמין כמה היה יפה וכמה הוא יפה
Actually, earlier in Exodus 21:18-19, the text indicates that an assailant will pay for the healing of his victim:
18: יחוְכִי יְרִיבֻן אֲנָשִׁים וְהִכָּה אִישׁ אֶת רֵעֵהוּ בְּאֶבֶן אוֹ בְאֶגְרֹף וְלֹא יָמוּת וְנָפַל לְמִשְׁכָּב
19: יטאִם יָקוּם וְהִתְהַלֵּךְ בַּחוּץ עַל מִשְׁעַנְתּוֹ וְנִקָּה הַמַּכֶּה רַק שִׁבְתּוֹ יִתֵּן וְרַפֹּא יְרַפֵּא
18: And if men quarrel, and one hits his fellow with a stone or with a fist, and he does not die but is confined to bed,
19: if he gets up and walks about outside on his support, the assailant shall be cleared; only payment shall he give for the idleness caused, and he shall provide for his cure.
This implies that the assailant pays for the damage caused to his victim rather than having his own body part damaged in retribution.
So if you ever find yourself living in ancient Israel with only eye, you should not fear losing it as some sort of penalty.