wren

Albert would rely on them to get by in most situations, to adapt to his environment with very little hindrance, and to adjust quickly in time to respond to potential threats. The transition from brightly lit rooms to darkness isn't a problem either. Most people who utilize tinted glasses adjust better to their night vision than the average person. He would be able to see perfectly fine in the dark woods.

Additionally, given the time period, this would not hinder his past military experience, his service with the R.P.D or his ability to function as a scientist and researcher in an Umbrella Lab. The military (the Army specifically) had a more relaxed view on their soldiers' eyesight exams. As long as he could see the letters on the vision exam, he was able to pass the medical requirements for his service.

When Albert later became infected, we know based on documentation in the early games that the viruses have a habit of exacerbating pre-existing conditions, and can affect mood and vision. Since Albert would already have a pre-existing medical condition with his eyes, the virus mutating them as his only visible change makes sense. The virus only mutates that which has been damaged to repair and strengthen it. His eyes were his weak point.

The fight against Albert in RE5 furthers this aspect by making the focal point of the fight involve fluctuating the light sources in the environment to affect his ability to adapt and adjust. It doesn't completely blind him since Albert can still find Sheva and Chris once he has adjusted to the lighting shift, but it does cause him immense pain. The mutation of his eyes forming slit pupils would only add to his struggle to adjust between various light sources.

While thinking on that, immediately before the fight with the light switches, we have the infamous 'sunglasses throwing scene' where Albert takes off his sunglasses to throw them at Chris. While this takes Chris off guard, we also see the environment is much more comfortable for Albert to adapt to. Low lighting, no excess light sources, close proximity targets. While being extremely eccentric, it also shows his level of comfort in that moment which appears to take even Chris by surprise. He's so accustomed to seeing Albert with them on at all times that it clearly alarmed and shocked him to see Albert willingly remove them.

It makes me think how much of a well known fact Albert's visual impairment would have been to S.T.A.R.S. Infiltration missions or trainings with flashbangs or floodlights would have to be carefully taken into consideration so as not to hinder his approach with the rest of the team. Or would effect his position in the six man cell, most likely utilizing Chris as a fleshy human shield to block him from (excessive) exposure.

Even catering to their Captain due to the fact he'd be much more prone to frequent migraines and headaches, or eye strain. How often would someone else in S.T.A.R.S. have to be the designated drivers because reflective or neon signs, oncoming car lights or flashing emergency lights at night would hinder his ability to see his surroundings. Or even weather conditions like heavy snow. So many simple matters that most people would have taken for granted with the ease of their day to day, would be a big deal for someone in Albert's position, yet he would need to trust S.T.A.R.S. enough to not only plan for that shortcoming but to also divulge that information to his team so they can adapt around it. We see during the intro in RE1 that nobody moves too far ahead of Albert or turns their flashlights in his direction. Other members flash their lights at each other, but not Albert. Even Barry and Chris take extra care that when sweeping a direction, they lower their lights to the ground first when passing by Albert, or turn away from him so as not to direct any lights his way while the three of them lead their unit. This shows forethought and an awareness of his circumstances to avoid accidentally affecting him.

Bonus thought: