How about English? You could use a massive overhaul in just English. The first "photo document exposit device" in the game, the newspaper clipping in Mr. Felton's desk, is a nighmare to try and read, let alone get any real story elements from. Same goes for many such objects.

Words are interpreted wrong, Diseases are interpreted and presented incorrectly, sentence structure is a mess, even the subtitles are incorrect. Many of the syndromes and diseases you are using in your narritive are simply wrong so let me help.

Keratosis: This is a term that is used to describe thick growths on the skin such as warts or calluses and is used in conjunction with "Actinic" Keratosis and "Seborrheic" Keratosis. These can develop with overexposure to UV light.

Photosensitivity: Or "Sun Allergy" is an immune system reaction triggered by sunlight which results in skin reactions varying from itchy eruptions to inflammed patches on the skin AKA like sunburns but these are triggered by your immune system.

One is an immune system reaction, the other is yet undefined by science but may be heriditary as not everyone developes them and are basically skin cancer precursors and may take decades to develop if they even do.

These two terms are not able to be used in conjunction with each other to form your term "Keratosis Photosensitivity" as they are both their own terms, and would not develop together. They are independant afflictions.

You are trying to fit terms into your narritive that do not work: Sensitivity to the sun, and blindness caused by it by using your term "Keratosis Photosensitivity", its not a thing.

What could have possibly been a better match for the affliction you are going for would have been "Photophobia", discomfort or abnormal pain to the eyes due to light exposure. Not to be confused with "Heliophobia" or the direct fear of light.

Photophobia actually covers everything you described: Pain in the eyes, nausea, redness itching, swelling, changes in hearing, blurred vision. So again, either a gross misinterpretation or a severe lack of a simple Google research session by whoever wrote and edited that bit of content.

Sorry to have gone on for so long, but I loved the game. But the editing and the writer of the narrative probably could have used a partner to help fix glaring and immersion breaking issues like these. And if you are going to put so much emphasis of the story into these exposit devices, then they should at least be somewhat accurate. Even in fiction writing, writers are held to the predefinition of known words and terms so as to not confuse the audience. Creative Writing College Course 101.

Just my 2cp. Cheers.