Answer
Pressing beside the nose reduces drainage into the bloodstream, which may reduce systemic side effects.
Sources for this answer
- Brimonidine tartrate/Timolol 2mg/ml + 5mg/ml eye drops, solution — Current selected SmPCemc · Summary of Product Characteristics
- NHSNHS · NHS medicine guidance
General medicine information. Follow the instructions for your own medicine and speak to a pharmacist or clinician about your individual circumstances.