Can LVLMs Uncover the Truth Behind Visual Illusions? An Analysis of Perceptual and Reasoning Capabilities

Liangjie Zhao, Jiaqing Lyu, Kexin Tang, Zecheng Fang, Rong Yin, Yulan Hu, Da Li, Jianing Li


Abstract
Large Vision Language Models have integrated reasoning capabilities, elevating cognitive performance to new levels. However, existing evaluations either focus solely on perception or rely on specific domains such as maths or coding. Evaluation for reasoning capabilities that align with an open-world environment is still required, especially one that considers perception and reasoning jointly. To bridge this gap, we propose to evaluate LVLMs by exploiting visual illusions as a diagnostic tool. Visual illusions are phenomena in which the human visual system misinterprets objective signals, resulting in an understanding that deviates from reality. We constructed IllusionReasoning, a benchmark of illusion images collected from the real world, incorporating diverse annotated question-answer pairs. Based on IllusionReasoning, we show that the reasoning capabilities of a wide range of LVLMs are not as advanced as claimed. Our work provides new insights into LVLMs and offers future direction for optimisation.
Anthology ID:
2026.findings-emnlp.1506
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
32061–32073
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1506/
DOI:
Bibkey:
Cite (ACL):
Liangjie Zhao, Jiaqing Lyu, Kexin Tang, Zecheng Fang, Rong Yin, Yulan Hu, Da Li, and Jianing Li. 2026. Can LVLMs Uncover the Truth Behind Visual Illusions? An Analysis of Perceptual and Reasoning Capabilities. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 32061–32073, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Can LVLMs Uncover the Truth Behind Visual Illusions? An Analysis of Perceptual and Reasoning Capabilities (Zhao et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1506.pdf