Are toddlers scared of the dark? My 18 month old sleeps alone in his room. Should I be leaving the light on?

Fear is a emotion which is developed with conscience and maturity. Though toddlers are not aware of it, they gradually develop it over time. Sleeping alone develops individuality and inculcating that at early stage is very important. Leaving light in is not an option; not even economically. The kid should know the difference between day and night. Not just adults, kids and babies too have dreams; and few could be bad which might wake up us up in mud of night. The room should be dark, but you can still choose for dim bed bulb that throws some light when u open your eyes in the night.