Winter teaches you to place light thoughtfully. A lamp at the right height removes strain that you did not know you were carrying. Shadows soften. The surface of your work grows even. Errors reduce because your body is not busy fighting glare.
Look at your workbench, literal or metaphorical. Does the light help the task. Is it warm enough for comfort and cool enough for clarity. Move the lamp. Raise the shade. Clean the bulb. Small changes compound. Attention that was defensive becomes creative.
Consider reflections, too. A bright rectangle on a screen or a glossy page can pull energy out of the eyes. Angle the surface. Shift your seat. You will feel the difference as relief, which is a quiet kind of speed.
Good light is not luxury. It is a basic tool. Once set, it disappears, which is how you know it is working.