Blindsight

Blindsight Is one of the memes added with the Ideology DLC.

It elevates the status of blind pawns and improves the psypowers of blind psycasters.

Advantages

Blindsight gives up to +15 mood boost to blinded pawns and +30 opinion from other pawns.
Increases blinded pawns psypower by increasing their psychic sensitivity.
Allows crafting blindfolds, which provides protection, cold insulation and +2 mood boost for sighted pawns.
Blind pawns stats are unaffected by light and darkness.
Blind pawns ignore other pawns beauty status.
Blinding greatly decreases the pawn value.
Unlocks Medical specialists.

Disavantages

Blindsight gives up to -6 mood boost to non-blinded pawns and -5 opinion from other pawns.
Blinded and blindfolded pawns are severely limited on the number of activities they can perform effectively.
Blind pawns ignore rooms beauty status.
Disables the Darkness meme.

Blind psysense: Strong

This precept increases the user psychic sensitivity when blind:

Blind bonus: +30% psychic sensitivity.

Regardless of this precept, each point of sight bellow 50% gives the user +1% psychic sensitivity. That means you normally get:

Sighted wearing blindfold: +30% psychic sensitivity.
Total blindness: +50% psychic sensitivity.

And with this precept:

Total blindness: +80% psychic sensitivity.

Blinding ritual

If satisfying, this ritual will give the pawn a psylink upgrade or unlock new psychic powers.

You can repeat the ritual by recovering the pawn sight, that means you can effectively trade Bionic eyes, Healer mech serums and Resurrector mech serums for psychic powers.

You can also heal the pawn eyes in a Biosculpter pod if he follows a non-Blindsight ideoligion. Together with the Transhumanist's "Biosculpting: Accelerated" this is one of the most efficient ways to farm psychic powers because the pawn doesn't have to be in the Blindsight ideoligion to be the Target of a Blinding ritual.

Affected activities

Before blinding a pawn, it is important to consider what activities are affected by sight.

Activities that are not affected by blindness:

Taming, Training, Social, Hauling, Cleaning and Meditation.

Activities that are slower with blindness:

Hunting, Cooking, Crafting, Art and Research.

Activities that have lower yield with blindness:

Mining, Butchering, Plants, Milking and Shearing.

Activities that might result in failure with blindness:

Construction and Medical.

Pawns dedicated to cleaning, hauling, socializing and mediating are the ideal pawns to blind.

If you are only taming and training without milking or shearing anything then animal handlers are also a good option to blind.

Hunters, cookers, crafters, artists and researchers can be blinded with only a reduction in work speed.

Builders and doctors are the worse options to blind since they can result in losing expensive materials, bionics and lives.

Strategies

Blinding overall provides more benefits than wearing a blindfold but compromises the pawn fighting abilities while a blindfold can be taken out during a raid. Therefore, full blindness is better suited for pure psycasters or pawns carring weapons with forced miss radio such as EMP grenades. Alternatively, careful shooters pawns, shooting specialists and Gunlinks can help overcome the accuracy lost.

Blinding is particulary useful in slaves. Blind slaves add very little wealth to your colony, have a lower chance to rebel since they are technically hurt and are fairly harmless in case a rebellion does happen. They can effectively use EMP grenades, EMP launchers and Smoke launchers since those weapons don't have aim penalty from blindness and also don't increase slave rebellion chance. Also, the extra cold insulation from blindfolds might just be enough to allow them wear Slave body straps on cold biomes. They will have increased psychic sensitivity and don't use psy powers if they rebel, therefore, the nobles of the empire which already have psy powers make really good candidates for slavery with support combat roles.

Since blinding is not ideal for a lot of pawns, Blindsight is better used together with another Ideoligion. That way you can have a few blinded pawns enjoying the benefits of their blindness without affecting much their activities while the rest follows another ideoligion that doesn't includes Blindsight and therefore are not sad for not being blind. For example, it might be worth it having a "blind worker" Ideoligion for cookers, crafters, cleaners and haulers and a "sighted elite" Ideoligion for those who need to keep their sight. Only your starting Ideoligion and the ancient's Ideoligion can have Blindsight.

Blind pawns are unaffected by light and darkness, so ideally you should fight in darkness so your enemies get a move penalty and you don't. Consider keeping a Sun Blocker active for a permanent fight advantage if it doesn't hurts your energy and food production.

Blind pawns ignore pawns beauty status, so you can give them Stoneskin glands without penalty to opinion.

Blind pawns ignore rooms beauty status, so you won't get negative mood buffs for dirty rooms, but you also won't get positive mood buffs for beautiful rooms.

It is not a good ideia to blind medical specialists, but they can still wear blindfolds while not doctoring and act as psycasters during combat. Unlike pawns incapable of violence, medical specialists can equip an Eltex staff if you give them before assigning the role.

Even if you don't want to blind anyone, Blindsight is still a useful meme that give access to medical specialists and the blinding ritual which can be used to farm psychic powers.