Nasal drops and sprays break the fast if the liquid reaches the throat, because the nose is a recognised passage to the stomach; this is why the Prophet ﷺ told Laqīṭ ibn Ṣabirah, "Be thorough in sniffing water up the nose, unless you are fasting." Eye drops and ear drops are not eating or drinking and have no open channel to the stomach, so the strongest view — held by many verifying scholars, including Shaykh Ibn ʿUthaymīn — is that they do not break the fast. A number of earlier scholars, however, treated the eye and the ear as passages to the interior and held the fast to be broken, or at least broken if one tastes the drops in the throat. Since the matter has legitimate ikhtilāf, the safest practice is to use eye and ear drops after Maghrib where possible, and to keep nasal sprays for the night unless there is genuine medical need.
Q&A · Fasting
Do eye drops, ear drops, or a nasal spray break the fast?
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.