Construct and Fort saves vs Blinding effects.
From what I'e seen(monster abilities, spells, SLAs, etc), an effect that would render one blind is a fort save. Constructs are immune to for saves except those that work against objects and are harmless. Constructs are not immune to being blind.
http://www.d20pfsrd.com/bestia...-types#TOC-Construct
Traits:
A construct possesses the following traits (unless otherwise noted in a creature's entry).
No Constitution score. Any DCs or other Statistics that rely on a Constitution score treat a construct as having a score of 10 (no bonus or penalty).
Low-light vision.
Darkvision 60 feet.
Immunity to all mind-affecting effects (charms, compulsions, morale effects, patterns, and phantasms).
Immunity to bleed, disease, death effects, necromancy effects, paralysis, poison, sleep effects, and stunning.
Cannot heal damage on its own, but often can be repaired via exposure to a certain kind of effect (see the creature's description for details) or through the use of the Craft Construct feat. Constructs can also be healed through spells such as make whole. A construct with the fast healing special quality still benefits from that quality.
Not subject to ability damage, ability drain, fatigue, exhaustion, energy drain, or nonlethal damage.
Immunity to any effect that requires a Fortitude save (unless the effect also works on objects, or is harmless).
Not at risk of death from massive damage. Immediately destroyed when reduced to 0 hit points or less.
A construct cannot be raised or resurrected.
A construct is hard to destroy, and gains bonus hit points based on size, as shown on the following table.
Proficient with its natural weapons only, unless generally humanoid in form, in which case proficient with any weapon mentioned in its entry.
Proficient with no armor.
Constructs do not breathe, eat, or sleep.
Examples of things the render one blind.
http://www.d20pfsrd.com/magic/...b/blindness-deafness
http://www.d20pfsrd.com/bestia...on/dragon-mithral-kp
http://www.d20pfsrd.com/bestia...r-listings/fey/nymph
Now, Tinna has pointed out that there are some blinding effects that have no save(power word blind). But I have pointed out that those effects that require no save are illegal if they also require no attack action. To make one arena legal a save or attack action is needed and more than not, a blind effect will require a Fort save. So, in fairness of the arena, would a stream of liquid substance that would cover an object just the same effect Tinna the construct?
The only exception I've seen so far being, Glitterdust.
Can someone paste the code to NOT include Tinna and Grunyar?