Some common eye exam charts--notice the patterns:
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ZFTPE TPECL CFEFD
FTPEO OZFTF ZFTPE
ZBDEF CPEFD TPEOL
DZFTP ZFTPE FTPEO
TPEOL FTPEO DZFTP
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COFEP OBPTL FDOBC
ZFPDE ZBDEF ZBEFD
OBPTL PTFLE COFEP
PTFLE ECPFD ZBDEF
ZBDEF ZBEFD OPFED
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PTFLE EPTFL FLEPT
EPTFL FLEPT LEPTF
LEPTF TFLEP PTFLE
FLEPT PTFLE TFLEP
TFLEP LEPTF PTFLE
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