You might be seeing a pattern here! It's not necessarily about the wattage, it's about the kind of light you're seeing. I also sew in an upstairs bedroom on the back of the house. It has only one small window so daytime or night, lighting is always an issue. I simply replaced all the bulbs in the overhead fan light as well as the desk lamp by my machine with daylight bulbs. They are definitely more expensive than regular bulbs, but have made a huge difference to my aging eyes.
I also have three small cliip-on LED lamps from Lowe's that I have strategically placed throughout the room for task lighting. One is at the ironing board, one at the embroidery machine and one at the serger. These are not the tiny ones that clip onto the machine itself. These have a flexible metal goose-neck about 18" and about 30 very bright LED bulbs in each. They were about $20 each.