There is some confusion here. As Stonebridge asks, it is better to see the context of the original question.
A current is a measure of the flow of electrons and electrons cannot flow unless there is an emf driving them. ergo no emf, no current.
So current is determined by voltage and resistance in a real world application.
The following is not required to answer a GCSE/A-level question. It does however show why there is difficulty in interpreting the OP's question:
Chapmouse is correct in identifying that standard light bulbs are marketed as having a brightness as a function of power consumed at the standard mains supply voltage of 230V a.c. This is so that consumers can easily choose a bulbs relative brightness based on the specified power rating.
The reason power is used to identify brightness is that there are a multitude of variables that affect the light output: dimensions and shape of the filament, conductor material (normally tungsten), gas filling (xenon, halogen etc), transparent enclosure (glass, quartz etc) etc.
But there is no industry standard that says any given light bulb at a certain power rating, must produce a given output of light. Moreover there is no specification for the colour temperature of that light either and hence the perceived brightness of the bulb.
So a manufacturer will state a power rating and will have designed the light bulb to consume a standardised power at the standardised mains supply voltage. i.e. 30W, 60W, 100W, 150W etc @230V a.c.
If the supply voltage is varied but resistance is kept constant, then the current drawn by the bulb will also vary and hence the brightness will alter.
If the filament resistance is varied but the supply voltage is held constant, then the current drawn by the bulb will vary and hence the brightness will alter.
However if the current supplied to the bulb is held constant (constant current source) the only way of then varying the brightness is by controlling both the resistance and supply voltage as a combined function. i.e. the ratio V/R must also be held constant. But crucially P = V2/R. So the higher the current, the power dissiapated increases exponentially.
Stonebridge is correct that power, voltage, current, resistance are all linked and that varying any one will result in a change of brightness - on paper.
This is however purely mathematical in that the only physical parameters in practice that can be changed are the ones stated earlier.
And the only electrical physical parameter that is within a manufacturers control is the resistance of the filament.
Hence we get back to the OP's question: Is the context purely academic or is it real world application?