The objective lens is the lens closest to the specimen on a microscope. It's not actually the light that's darker, but the image of the specimen appears darker when using a higher magnification objective. Here's why:

* Higher magnification = Smaller aperture: Higher magnification objectives have smaller apertures (the opening that lets light through). This means less light reaches the specimen and the image.

* Less light = Darker image: With less light hitting the specimen and reaching your eye, the image appears darker.

Why do we use higher magnification objectives?

Despite the darker image, higher magnification objectives are essential for viewing smaller details in the specimen. While the image is darker, it's still possible to adjust the light source intensity or use a special condenser lens to improve illumination.

In summary:

The objective lens itself doesn't make the light darker. It's the smaller aperture of higher magnification objectives that results in less light reaching the specimen, making the image appear darker.