Small yet Assistive: Spatially-Aware Post-Training for Low Vision

Rishabh Choudhary, Shreyansh Raj, Umesh Goyal, Subh Kasyap, Shrestha Kumar, Sushovan Jena, Komal Kumar, Hisham Cholakkal, Aditya Nigam


Abstract
An estimated 1 billion people worldwide live with vision impairment, yet current vision-language models (VLMs) produce descriptions too vague for safe navigation by blind and low-vision (BLV) users. Large VLMs can generate high-quality audio-description-compliant narrations but cannot run on mobile devices; small VLMs offer competitive latency but lack spatial detail, directional cues, and hazard awareness for navigational assistance. We present Smol-VL-BLV, a compact VLM for blind and low-vision users that closes this gap using a 500M decoder transformer model and two post-training mechanisms: (1) teacher-student distillation and (2) Group Relative Policy Optimisation (GRPO) with a composite BLV reward targeting directional language, metric distances, and hazard detection. Because multi-stage post-training can induce catastrophic forgetting, we add a lightweight finetuning stage after the last stage GRPO finetuning to recover general descriptive quality while preserving BLV-specific spatial grounding. Our best model substantially outperforms the baseline across various benchmarks, including tasks: VQA, BLV captioning, OCR, and real-time observation. Compared with the baseline for relative improvement, it improves the Spatial score gain of 19.3%, and the Social score gain of 14.8%. It also increases OCR-Bench by 101.5%, and raises TextVQA accuracy by 44.2%. These results show that BLV-focused post-training improves both accessibility-specific spatial grounding and general visual-text reasoning. Deployed on a mid-range Android smartphone via Mixed-Precision Quantization, the model remains under 450 MB and generates descriptions in real time, demonstrating practical viability for on-device BLV assistance. Our model, dataset, and code will be publicly released.
Anthology ID:
2026.emnlp-main.2273
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
51690–51703
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URL:
https://aclanthology.org/2026.emnlp-main.2273/
DOI:
Bibkey:
Cite (ACL):
Rishabh Choudhary, Shreyansh Raj, Umesh Goyal, Subh Kasyap, Shrestha Kumar, Sushovan Jena, Komal Kumar, Hisham Cholakkal, and Aditya Nigam. 2026. Small yet Assistive: Spatially-Aware Post-Training for Low Vision. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 51690–51703, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Small yet Assistive: Spatially-Aware Post-Training for Low Vision (Choudhary et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.2273.pdf