Landlords and tenants can be responsible for light bulbs.
The Residential Tenancies Act does not explicitly state who is responsible for supplying or replacing light bulbs, so it’s a good idea to talk about this at the start of a tenancy and note what is agreed in the tenancy agreement.
It is standard practice however that the landlord supplies working light bulbs at the start of the tenancy, and the tenant replaces any that stop working, including ensuring that light bulbs are working when the tenancy ends. An exception to this may be if the light bulb cannot be accessed easily.