There would be written three letters k. f. r., i. e. Kafir, between the eyes of the Dajjal.
أَنَّ نَبِيَّ اللَّهِ ﷺ قَالَ الدَّجَّالُ مَكْتُوبٌ بَيْنَ عَيْنَيْهِ ك ف ر أَىْ كَافِرٌ
[Machine] The Prophet ﷺ said: "Verily, the Dajjal (false messiah) will have on his left eye a mark written between his eyes that says 'kafir' (disbeliever)."
أَنَّ النَّبِيَّ ﷺ قَالَ إِنَّ الدَّجَّالَ مَمْسُوحُ الْعَيْنِ الْيُسْرَى عَلَيْهَا ظَفَرَةٌ مَكْتُوبٌ بَيْنَ عَيْنَيْهِ كَافِرٌ
Dajjal is blind of one eye and there is written between his eyes the word" Kafir". He then spelled the word as k. f. r., which every Muslim would be able to read. (Using translation from Muslim 2933c)
أَنَّ النَّبِيَّ ﷺ قَالَ الدَّجَّالُ مَمْسُوحُ الْعَيْنِ مَكْتُوبٌ بَيْنَ عَيْنَيْهِ كَافِرٌ يُهَجَّاهَا يَقْرَؤُهُ كُلُّ مُسْلِمٍ ك ف ر
Request/Fix translation
"إِنَّ الدجَّال ممسوخُ العين اليسرى عليها ظَفَرَةٌ ، مكتوب بين عينيه كافِرٌ".