Reading a text without spaces in an alphabetic language causes disruption at the levels of word identification and eye movement control. In the present experiment, we examined how word discriminability affects the pattern of eye movements when reading unspaced text in an alphabetic language. More specifically, we designed an experiment in which participants read three types of sentences: normally written sentences, regular unspaced sentences, and alternatingbold unspaced sentences. Although there was a reading cost in the unspaced sentences relative to the normally written sentences, this cost was much smaller in alternatingbold unspaced sentences than in regular unspaced sentences.