expeyes: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/expeyes - from package: expeyes

You may install the required package with command apt-get install {package}
Error in other languages:
expeyes: bevel nie gevind nie
expeyes: comandă negăsită
expeyes: comando não encontrado
expeyes: commande introuvable
expeyes: command not found
expeyes: käsku ei ole
expeyes: không tìm thấy lệnh
expeyes: komanda nerasta
expeyes: Kommando nicht gefunden.
expeyes: kommandot finns inte
expeyes: komut yok
expeyes: nie znaleziono polecenia
expeyes: níor aimsíodh an t-ordú
expeyes: no se encontró la orden
expeyes: no s'ha trobat l'ordre
expeyes: opdracht niet gevonden
expeyes: parancs nem található
expeyes: perintah tidak ditemukan
expeyes: príkaz nenájdený
expeyes: příkaz nenalezen
expeyes: команда не найдена
expeyes: командата не е открита
expeyes: 命令找不到
expeyes: コマンドが見つかりません