If you can position your desk in front of, or near a window, that would improve things cosiderably. 

Use a flexible LED desk lamp. A flexible head is extremely important.

The best way to getting the idea indoor office lighting is a mix of natural and LED lights.

Use dummable gimbles and spotlights on the ceiling, ideally cool white (cool white is good for alertness). These will enable you to direct the light in exactly the way you want it, and the dimmers will enable the capability for precise brightness.

Replace dark walls and curtains with light coloured ones, this will make a huge difference to your office and will not cost too much.

Table lamps with flexible heads are critival. Make sure that the light is not reflected directly into your face (eg from a computer screen) and also that the light is hidden by a diffuser so it is not shining into your eyes.

I recommend cool white (4000K) for home office.

Layering different lights will create the best effecyt. For example, a desk lamp together with a floor lamp and downlights.

Make sure you set up your computer so that in the daytime, the sun is not facing you or behind you.

In a home office you need bright light but diffused so that it is not too harsh - you can get that from reflective light eg bouncing floor-mounted spotlights into the ceiling.

I like minimalist lighting in my home office - one table lamp and one desk lamp.

Don't forget pendant lights! One or two nice pendants will cast a diffuse light over your home office and will give you just the right lighting if dimmable.

There are some superb ring type pendants lights that are perfect for home offices. They look very stylish and also provide excellent lighting.

The brightness of a home office should be ideally 2500 to 5000 lumens.