Does colour temperature affect eye strain?

Less than brightness and glare do. An evenly diffused warm light at adequate brightness is easier on the eyes than a brighter lamp with visible point sources, whatever its rated colour temperature. Diffusion and positioning matter more than the number on the box.

Why it happens

Most reported eye strain from a desk lamp comes from contrast, not colour. A bright pool of light in a dark room forces constant pupil adjustment as your gaze moves between the page and the surroundings. Raising ambient light in the rest of the room helps more than changing the lamp.

Glare is the second factor, and it is a construction question. A frosted polycarbonate or acrylic diffuser turns a row of point sources into an even strip. A lamp with bare visible diodes will feel harsh at any colour temperature.

Colour temperature does affect alertness and sleep timing in the evening, which is a real effect — but it is a different question from whether your eyes ache after an afternoon of work.