Blindness in GURPS, and the "Star Trek" setting 2262...

[Pursuivant]

FWIW, Kayla Detmer in the recently-finished Discovery series has a bionic eye c. 2257, with an obviously inhuman appearance. Unfortunately, the Memory Alpha article for her doesn't have any pictures of her c. 2257 ocular implant.

Another officer with bionics, serving prior to 2258 is LT Ariam . She's clearly a partial cyborg with two artificial eyes.

Detmer's bionic eye is obviously reliable enough to give her full normal vision, since she's Discovery's helmsman for the entire 2nd season. Ariam's eyes also appear to give full range of vision.

A c. 2257 style bionic eye, which provides no extra functionality uses Blindness (Mitigator, -70%) [-15]; Distinctive Feature (Obviously Artificial Bionics) [-1] and possibly reduced Appearance.

RL Blindness adaptability aids include service dogs (or equivalent) and echolocation. The latter allows a surprising level of adaptation. It could be treated as a Perk, levels of Acute Hearing or as a limited form of Detect or Vibration Sense.

The ability to use a White Cane and similar devices effectively should also be a perk for the non-Blind.

A "native" blind person will also have the Braille version of their written language as their native language. Someone who goes blind must relearn to read in Braille, effectively making it a Written Language [1-3 points] or a Perk depending on how the GM wants to handle it. Native braille readers might also have levels of Acute Touch.

Since Glaucoma usually affects people by narrowing their field of view, giving them some form of Restricted Vision (p. B151) there's a chance that a person affected by the condition just has Tunnel Vision [-30] and Bad Sight (Uncorrectable) [-25], representing near blindness. Unfortunately, the combination is worth -55 points, which is more than the cost of Blind. I'd model the Bad Sight aspect as a +25% enhancement to Tunnel Vision, giving a cost of 38 points.

Finally, since most forms of glaucoma are treatable by 2024, it's quite likely that there are permanent cures for it by the mid-23rd century, analogous to the later Retinax V.

If that is the case, and since canon has established bionic eyes as a mature technology used by Starfleet by 2257, it's quite possible that your character has suffered a recent injury and is still recovering since she's using a cane rather than implants.

Unless you've established that her glaucoma is indeed genetic and incurable, one explanation for her problem is exposure to sudden low pressure, like explosive decompression or extended exposure to a thin atmosphere, which damaged her eyes without (permanently) affecting the rest of her body.

Another condition which can damage the optic nerve, like glaucoma, is exposure to intensely bright light such as lasers or nuclear explosions. Since it's Star Trek, sudden, untreatable glaucoma could also be triggered by exposure to all manner alien threats.