Startup Idea: Customizable Screen Contrast for Visually Impaired

Startup idea to develop a program enabling visually impaired users to choose custom brightness/contrast settings per page. Additional features can include a pinned toolbar panel full of preset options and potential bundle with a graphic equalizer. 'Page Optimizer' could serve as a fitting name for such a product.

I am visually impaired and am particularly sensitive to screen-to-screen variation in brightness and contrast settings. I am able to manage this problem by toggling hi-contrast settings on and off for each screen., but it becomes an all-or-none change. I would love a simple program that allowed the user to select custom brightness/contrast settings on a per-page basis. Perhaps a small, always-on-top window (or panel pinned to the toolbar), which contains a collection of preset options--buttons that represent a variety of contrast and brightness settings. This way, the user could remain in their web browser, and select custom page settings on the fly. I think a simple, inexpensive fix would be marketable. $1-$10, depending on branding and sophistication. This could be bundled with a graphic equalizer, etc., to expand market potential. Maybe call it the "Page Optimizer".