Another interpretation of "from seeing" (Genesis 27:1): it was from the force of that seeing. At the hour when Abraham our father bound Isaac his son upon the altar, the ministering angels wept, as it is written, "Behold, their valiant ones cry out in the street" (Isaiah 33:7). And their tears dropped down into the eyes of Isaac and were imprinted within his eyes. And so, when he grew old, his eyes dimmed.
How the Tears of the Angels Dimmed the Eyes of Isaac
Yalkut Shimoni on Torah 114:2
דָּבָר אַחֵר מֵרְאֹת, מִכֹּחַ אוֹתָהּ רְאִיָּה בְּשָׁעָה שֶׁעָקַד אַבְרָהָם אָבִינוּ אֶת יִצְחָק בְּנוֹ עַל גַּבֵּי הַמִּזְבֵּחַ בָּכוּ מַלְאֲכֵי הַשָּׁרֵת דִּכְתִיב (ישעיה לג, ז) "הֵן אֶרְאֶלָּם צָעֲקוּ חֻצָה" וְנָשְׁרוּ דִמְעוֹתֵיהֶן לְתוֹךְ עֵינָיו שֶׁל יִצְחָק וְהָיוּ רְשׁוּמוֹת בְּתוֹךְ עֵינָיו וְכֵיוָן שֶׁהִזְקִין כָּהוּ עֵינָיו.