When changing to a higher magnification, it is generally more desirable to increase the light. This is because higher magnification lenses tend to have a smaller aperture, which means they allow less light to enter. As you zoom in on your subject, the amount of light that reaches your eyes or the camera sensor decreases.
With increased magnification, the details of the specimen become clearer, but they also become darker due to the reduced light. To counteract this effect, increasing the intensity of the light helps to illuminate the subject better, making it easier to see fine details. In microscopy, for instance, using a brighter light source or adjusting the light condenser can enhance visibility at higher magnifications.
In summary, while it may seem logical to decrease light intensity at higher magnifications to avoid glare, in practice, increasing the light is usually more beneficial for clarity and detail observation.