Consult with a real estate attorney who handles nuisance matters and have them start by writing a demand letter and then filing suit on your behalf. This would be a private nuisance.
I'm a real estate broker in addition to being an attorney.
I agree with Mr. Parikh. A "nuisance" is a common law remedy (from case law) that precedes zoning laws and building codes based on statute laws passed by legislatures and administrative boards. It is defined as a use of real property that unreasonably interferes with a neighbor's use and "quiet enjoyment" of his own property, such as noise, dust, odor or "glare" which is the condition of which you speak.
While you might not be entitled to demand the neighbor have no lights so you can use a telescope and view the stars, overly bright spotlights which serve no useful purpose and spill over onto your property sound like an actionable nuisance for which you can seek an injunction and perhaps even money damages. Most lighting fixtures can be directed not to shine on a neighbors property, and any kind of commercial development (i.e., more than a single family house) must usually undergo a site plan review which would contain a "lighting plan" demonstrating that the lights would not spill beyond the property borders beyond a low level, like several footcandles at most.
Also, most commercial fixtures have "cutoffs", which are lenses or metal flaps which are built into the light fixture ("luminaire") which prevent the lights from spilling outward horizontally. Any kind of commercial site plan review will review the specifications of the luminaires to require "sharp cutoffs" to address this problem.
Retain a lawyer. It sounds like you have made reasonable requests and it's lawsuit time. Your chances of prevailing sound pretty good to me.
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