From a Jain perspective, the core aim is non-violence (ahimsa) and purification of the mind, not elaborate external sacrifices. Yajna smoke is not a central or essential Jain practice, and many Jains today prefer simpler, smokeless ways to express devotion or purify the environment.

Regarding eyes and lungs:

• Smoke of any kind can irritate the eyes and irritate or irritate the respiratory system, especially for people with asthma or other lung sensitivities.
• Prolonged or strong smoke exposure can cause discomfort, coughing, or breathing difficulty.

Practical guidance (in line with Jain emphasis on ahimsa and minimizing harm):

• If you must participate in or witness a yajna, ensure good ventilation or perform in a well-ventilated space to reduce smoke exposure.
• For those with respiratory concerns, prefer smokeless or minimally smoky rituals, or substitute with meditative or devotional practices that do not produce smoke.
• Prioritize the safety and well‑being of all beings; avoid unnecessary suffering or irritation to any creature.

If you want, I can point you to a relevant JainKnowledge.com page that discusses Jain views on ritual offerings and non-violence in practice.