Judges 16:28

וַיִּקְרָא שִׁמְשׁוֹן אֶל ה' וַיֹּאמַר אֲדֹנָי ה' זָכְרֵנִי נָא וְחַזְּקֵנִי נָא אַךְ הַפַּעַם הַזֶּה הָאֱלֹקים וְאִנָּקְמָה נְקַם אַחַת מִשְּׁתֵי עֵינַי מִפְּלִשְׁתִּים

Samson called out to G-d, saying, "G-d, please remember me and please strengthen me just this once, O G-d, that I may avenged of the Philistines for one of my two eyes."

If Samson wanted vengeance on the Philistines for the loss of one of his eyes, what did he want as a reward for sacrificing the other? Rashi cites the Talmud Yerushalmi that he wanted to use that merit to be assured of entry to the Next World. At this time, however, he wanted to use some (but not all) of his accrued merit to avenge himself on the Philistines.