Choosing the right lens for water activities is key and it is important to understand that the lens choice for stream fishing may not be the same as for offshore boating, on the beach or at the pool. The activity, geographic location, weather condition and time of day are all factors to be considered.
Two sunglass lens features for use in and around the water that remain constant are full UVA and UVB protection and polarization (except in cases where they could interfere with polarized LCDs or instrument screens).
LENS MATERIAL OPTIONS
Lenses are made from varied substrates. The most common for sport sunglass use are polycarbonate, glass, and nylon (polyamide).
Polycarbonate lenses are lightweight and shatter-resistant but not scratch-resistant and provide less visual clarity than glass and nylon.
Glass lenses offer the best visual clarity, and optimal scratch resistance but they can be heavy and do not have the same shatter resistance as do polycarbonate lenses.
Nylon lenses are lightweight, have visual clarity close to that of glass and do have a higher level of shatter resistance than glass but lower than polycarbonate. They can provide benefits of glass and polycarbonate.
LENS BASE COLOR AND MIRROR OPTIONS
The base lens color and applied mirror coatings affect how your lenses perform for activities in varied locations and weather conditions.
Polarized darker gray lenses with a blue mirror coating work great the while out or about deep open waters, lakes, on the beach or at the pool and in highly sunny, high glare conditions.
For inshore and shallower water activities, there will likely be objects that help to block or absorb some of the sunlight so when around, freshwater rivers, lake edges, and ponds, trees and other land objects can cast a shadow on the water, making it difficult for your eyes to see into the water.
Polarized amber, copper and brown lenses perform well in these types of locations adding a green mirror is also beneficial.
For low light conditions, such as early morning, rose or yellow-colored lenses are a great option because they tend to make everything seem brighter. They are not recommended for full bright sunlight.
Photochromic lenses are a great option for any geographic locations where there are changing light conditions as well as for all day from dawn to dusk as the lenses lighten and darken accordingly. Make sure to know the lens level of transition from light and dark as there are many variations. You can be specific to your targeted uses.
Last point to take away: Know your lenses, their substrate, quality, spec details and be clear for the targeted use / customer.