ABSTRACT Clinical relevance The monitoring and controlling of pH is important when preparing solutions for ophthalmic administration. In the case of povidone‐iodine, dilution in an appropriate buffer is needed to improve its ophthalmic safety. Background Povidone‐iodine is a broad‐spectrum antiseptic agent that is commonly used in ophthalmic applications due to its cost‐effectiveness and accessibility. However, native povidone‐iodine has a pH of about 4.0 and is known to irritate the ocular surface. This study assessed whether adjusting povidone‐iodine formulation pH would influence its ex vivo ophthalmic safety, alongside its impact on antibacterial efficacy and storage stability. Methods One per cent w/v povidone‐iodine was diluted in normal saline, or 0.1-mol/l citrate or phosphate buffers to yield solutions with a pH ranging from 4.0 to 7.0. Ocular irritancy was evaluated using the bovine cornea opacity and permeability assay. Antibacterial efficacy was assessed by evaluating povidone‐iodine minimum inhibitory concentration and minimum bactericidal concentration at varied pH. Storage stability of the preparations was determined over 30-days at room temperature (20–25°C). Results Combining povidone‐iodine with phosphate buffer notably decreased ocular irritancy of the antiseptic. Surprisingly, combining povidone‐iodine with citrate buffer potentiated irritant effects of the preparation. Antibacterial efficacy of povidone‐iodine was reduced when formulation pH was increased from 4.0 to 7.0, although its general activity was retained. Finally, povidone‐iodine remained stable in both normal saline and phosphate buffer over 30-days. Conclusion Ophthalmic application of povidone‐iodine can be optimised by adjusting the pH of the formulation to 7.0 using phosphate buffer, reducing irritancy while maintaining adequate antibacterial efficacy and storage stability.