Polarised sunglasses with strong UV protection are essential. Snow, ice and water throw an enormous amount of glare and the bright conditions run for many hours in the polar summer. Use a retainer so they survive the wind and Zodiac boarding, and bring a spare if you depend on prescription lenses. Ski goggles are optional, useful on windy, snowy or wet Zodiac cruises, and plenty of passengers never touch them.
Bring goggles if you already own a comfortable pair, wear contact lenses, are sensitive to wind, or simply have the luggage space. Some people call them their favourite item of the trip. They don't replace everyday sunglasses though, which are easier for most landings and deck time.
Sunglasses are one of the items worth duplicating. Losing them over the side on day two of a ten day trip is a genuinely miserable outcome in that light.