There are a variety of ways to see, or get around seeing.  If you have
ultra dark or dark vision (see your race help) then you can see in
darkness.  Conversely, if you have light or ultralight vision, you will be
able to see in light and bright light.  Note that failure to have the
required level of vision means you will not be able to see at that light
level. 
Infravision also provides a means of see objects, only it shows them as
heat signatures.  Mindsight, enhanced sense of smell and enhanced sense of
hearing are limited, alternative means of detecting your surroundings.  
When in doubt, look for a torch, or a spell that casts darkness or light
(HELP SPELL LIGHT, HELP SPELL DARKNESS).

To get a list of the various light levels: 
HELP LIGHT LEVELS

SEE ALSO: help spell light, help spell darkness