This study aims to shed light on the contribution of universal versus language specific factors on reading. We examined eye movements of Arabic readers and analyzed effects specific to Arabic such as perceptual complexity, diglossia and morphology, in addition to universal factors such as word length and frequency. Twenty native Arabic speakers read continuous texts in Modern Standard Arabic (MSA) while their eye movements were monitored. A corpus-based analyses was carried to test effects specific to Arabic and effects of the benchmark eye movement factors. We found that perceptually more complex words received longer fixation durations, moreover, differences in processing words unique in MSA versus words shared between MSA and spoken Arabic Vernacular were found. This is the first indication for these effects during an eye movement reading task. However, the effect of morphological length was not significant when included in the model with all predictors. Lastly, the benchmark factors were significant showing effects for word length, word frequency and part of speech. Short and frequent words are processed faster than longer and less frequent words. Function words are often skipped. We conclude that eye movement of Arabic readers reflect proficient reading, yet they also exhibit an on-going challenge in processing the written language.