Theories Concerning the Cause of BlindnessThe light itself is only ever guessed to be the source of the blindness. This is, of course, somewhat confirmed by the accounts of those who can still see. However, there are some discrepancies that this doesn't fully explain.
- It seems biologically improbable for light to damage the eyes or optic nerves in a manner that wouldn't be immediately painful or obvious.
- The light and the triffids have no apparent connections. One bizarre event at the beginning of a narrative is a premise. Two risks stretching credulity, unless they have a common cause.
- There doesn't seem to be any large regions suffering from no blindness. Some places should have been heavily overcast during the 24 hour period, creating whole population centers of sighted people.
- This could be simply a case of a lack of omniscience on the part of the narrator, rather than the actual state of things.
- The outbreaks of diseases occur far too rapidly to be the result of an immediate decline in the standard of living. The diseases are explicitly acknowledged to be bizarre and unknown.
- The light is a side-effect of the actual cause of the blindness. Whether a weaponized satellite or alien object, the optic damage is caused by some kind of chemical, disease, or particle being dispersed into the atmosphere. The novel hints at this possibility.
- The light is actually a signal. It alerts triffids worldwide to release a spore that infects the eyes, causing permanent damage. This theory assumes the triffids were specifically engineered for this purpose, either by aliens or a government. The lack of followup invasion implies a government and a malfunctioning signal satellite.
Torrence is actually the heroTorrence, the red haired man Masen allows to be killed by Triffids at the end of the book, may actually be a 'good guy' and we have only Masen's point of view to tell us otherwise.
- Torrence is first seen when he draws a pistol and fires at Masen. However Masen at the time is chained to two other men and effectively being used a slave labour. Torrence may have already encountered such 'slave' arrangements and been attempting to rescue Masen from his captors. Torrence, having shot one and discovered the second 'dealt with' by Masen himself, makes no attempt to search for or deal with Masen despite the fact Torrence would have gotten a good look at him and Masen's only disguise was to hide in plain sight by pretending to be a blind man.
- Torrence mercy kills the plague victim that collapses from Masen's work group. Masen later helps mercy kill the un-named 18 year old girl after she comes down with plague a day or so later. While Masen uses pills instead of a pistol, both characters are effectively doing the same thing - easing the suffering of someone they are in no position to help.
- Torrence, in his end book role as an apparent member of the 'government' is attempting to implement a plan that allows the blinded to remain alive and useful. Masen, by comparison, rights off most of the blinded as being too many to save within the first 48 hours.
- Torrence and his three companions show incredible trust in Masen by allowing themselves to be tricked by the decoy party. For a group nominally completely dictatorial and brutal they make no attempt to collect all the weapons, post guards or obtain the keys to Masen's vehicle. Instead they happily accept Masen's hospitality and show complete trust in the entire arrangement.