Introduction The Müller-Lyer illusion is a convenient illusion in which the evidence or perceived length of a line varies based on whether it ends in an arrow tailor is arrowhead (Sakiyama & Gunji, 2013). Based on the Müller-Lyer illusion, the right vertical lines are apparently longer than the left vertical line, although these lines are of exactly similar length (see figure 1 below). The illusion results from the presence of the fins, which make the lines to appear different in length. When the fins are in, the line appears shorter while when they are out, it appears longer. According to Müller-Lyer, this was ‘confluxion’. Researchers have focused on further studies to understand this illusion, but without a consensus on specific perceived principles responsible for the illusion (Dewar, 1967b) while other explanations have been rejected (Cooper & Runyon, 1970). Psychologist, Richard Gregory had argued that the illusion resulted from a misapplication of size constancy scaling (Gregory, 1966). Generally, one can perceive an object in a more stable manner by considering the distance through size constancy. In this regard, an object should maintain its size irrespective of the distance, particularly with three-dimensional objects. Conversely, Delucia and Hochberg (1991) had difficulties providing explanations for the three-dimensional manifestation of illusion in their study. Gregory, however, had noted that errors could result when the same principle was applied to two-dimensional objects (Gregory, 1966). Conversely, other studies have demonstrated that Gregory’s approach does not provide any sufficient account for the illusion. For instance, it is noted that when two circles are introduced at the end the lines to replace fins, the illusion is still noted, yet there are no depth cues (see figure 2). Other studies have focused on gender differences to evaluate the Müller-Lyer illusion. For instance, a study by Baroun and Al-Ansari (2004) demonstrated that “gender had no significant correlation to the Müller-Lyer perception and Horizontal-Vertical illusion” (p. 33). Further, the evaluation of anxiety and gender differences on illusion had no significant difference (Baroun & Al-Ansari, 2004). Conversely, anxiety generally affected Müller-Lyer perception across both genders. Male and female with anxiety tended to depict higher illusion than did others with low anxiety. Dewar (1967a) showed that female had a little (though not significantly) higher illusion than did males, while male demonstrated a more rapid practice decline than did females during the evaluation of the magnitude and practice decrement of the Müller-Lyer illusion (p. 345). Figure 1: the Müller-Lyer illusion demonstrated with lines. Figure 2: Illusion still occurs when circles are used yet there are no depth cues. R. H. Day introduced an alternative approach to explain the Müller-Lyer illusion in which he asserted that the illusion resulted from conflicting cues (Day, 1989). In this regard, the actual length of an object (local) and the noted length of the figure (global) influence individuals’ perception to recognize the length accurately (Day, 1989). As a result, one line with outward fins would appear longer than the other line as both the local and global features interact and result in the compromised perception of the length of the line. Porac and Coren (1985) observed that the extent of s