Effect: This spell is similar to a light spell, except that it
lasts until negated (by a continual darkness or dispel magic spell) and its
brightness is very great, being nearly as illuminating as full daylight.

It can
be CAST into air, onto an object, or at a creature. In the third case, the
continual light affects the space about one foot behind the creature if the
latter makes its save. Note that this spell will blind a creature if it is
successfully cast upon the visual organs, for example.

DMG: As does a light spell, this will tend to blind a creature if it is placed on its visual sensory area.
The spell can also be placed upon
a smallish obiect, and a lightproof case subsequently used to encase the
obiect so as to make it dark until the covering is removed, i.e. a continual
light source which expends no fuel and will not blow out.
(Darkness spells are the bane of this device . . .)

ANSWER: It depends. The caster of the Dispel Magic would have
to roll percentile dice for each one to see if he successfully dispelled
each one. Dispel Magic affects everything within its range.

Answer: Either a Continual Darkness or Dispel Magic spell can negate
a Continual Light spell, whether the light had been placed over
an AREA or upon an object. Continual Darkness does not have to
be cast on the rod itself in order to ruin the light wand; the
darkness negates not only the light of the spell, but also the
magic which caused the rod to give off the light in the first
place. As long as the light wand is in, or is brought into, the AREA
of effect of the darkness spell, both spells would cancel each
other out. The same would be true if the wand were in a light-
proof container inside the AREA of effect: That container is not
magic-proof, and it is the magic itself, not just the visible effects
of that magic, which is negated.
    It’s important to understand the difference between a light
wand of this type and an item which is actually enchanted to
give off light, such as a Wand of Illumination or a Gem of Brightness.
When actual magic items are employed to produce
magical light, a darkness spell would at best only neutralize the
charge(s) currently in USE; the item is not rendered unusable as
long as other charges remain. For example, Continual Dark-
ness will negate the effect of a Gem of Brightness for only one
day — or not at all, if the owner of the item expends charges to
offset the darkness. A continual light wand, on the other hand,
is no more than a stick with a spell cast on it. When that spell is
dispelled, the stick’s light goes out for good (or until another
Continual Light is cast upon it).
    Dispel Magic is effective against a continual light wand, again
because it neutralizes the magic of the spell which was applied
to the rod. Dispel Magic cannot, as the spell description indi-
cates, weaken or negate the power of a “specially enchanted”
item such as the Gem of Brightness. The success of Dispel
Magic against a continual light wand or other similar object
depends in part on which particular kind of Continual Light was
used to manufacture the wand; the dispelling would be more
likely to succeed against the M-U version of Continual
Light, since that is a second level spell and the cleric and
illusionist versions of the same spell are third level incantations.
(Correction: Caster level, NOT spell level, affects the chance for a successful dispel).

A: Yes, on all counts. Each of these spells
can negate darkness of any sort, though a
light spell will ?go out? immediately after
negating such darkness, while the continual
light spell will last. Light or continual
light spell will negate only one darkness
effect at a time; thus, if there are two
darkness effects in the same area, the area
remains dark until two light effects are
used.
(153.7)

<Note that continual light cast on a gem will sometimes produce light of the same color as the gem. See T1-4, areas 214 and 215.>

Continual Light
This spell damages the eyes of someone/something at which it is
thrown. This “damage,” however, should be considered semi-permanent. It will make the figure -4 “to hit,” -4 on saving throws
that can be affected by sight (a figure saving versus polymorph or stone
can be blind or not blind—the s.t. would not change, but saving versus
a fire ball or lightning bolt would be more difficult if the figure could not
see it coming as well as he/she/it normally could), and -4 on AC in melee situations, since defense is more difficult.

This “damage” to the eyes does wear off, and a figure should
obtain a s.t. daily to throw off the effects. Of course, Cure Blindness or
even Cure Serious Wounds (or any better cure, NOT Cure Light
Wounds, however) will remove the effects at once. If Continual Light
actually caused full blindness it would be a fantastically powerful spell,
since it has a range component. What cleric would ever choose to cast
Cause Blindness by touch when he/she could do it at a 120-foot range?

Remember that if the TARGET makes its SAVE, the circle of light
still goes off behind him/her/it. Aiming at a figure’s eyes implies the
ability to make a smaller, more concentrated sphere of light for this one
circumstance, but if the SAVE fails the small sphere expands to full size. If
this were not true, people would be partially blinded every time they
entered a circle of continual light. Continual Light from a lantern can
blind as in a Light spell (see previous ruling on Light) only if the lantern
is opened right in the face of an opponent (10-foot range or so).
(TD33, LTH)
 

Continual Darkness: Its esrever causes complete absence of light.

MP.55