How To Keep Binoculars From Fogging Up And How Do They Float? – Clarity Scopes

How To Keep Binoculars From Fogging Up And How Do They Float?

Binoculars are essential equipment for various activities like hiking, bird watching, hunting, marine activities, and many others. These activities may involve extreme weather conditions, and the quality of the binoculars should not be compromised in such situations. The ability of a binocular to float and not fog up is an essential aspect that makes it stand out in the market.


Fogging is a common problem that occurs in binoculars when the temperature of the lens' surface drops below the dew point, leading to condensation. This can be a nuisance when viewing objects, and it may also damage the binoculars in the long run. Therefore, manufacturers of binoculars have developed ways to combat fogging.

  1. Anti-fog coatings One of the ways of preventing fogging in binoculars is through the use of anti-fog coatings. These coatings are applied on the lens surfaces and act as a barrier against moisture that may cause fogging. The coatings are hydrophilic, which means that they attract and retain moisture, hence preventing it from condensing on the lens' surface.
  2. Nitrogen Purging Nitrogen purging is another method of preventing fogging in binoculars. This process involves filling the binoculars with nitrogen gas, which replaces the air and prevents moisture from entering the binoculars. Nitrogen purging creates a dry environment inside the binoculars, thus preventing fogging.


Apart from preventing fogging, binoculars that float can be very beneficial, especially for marine activities. These binoculars are designed to stay afloat in water, making them easy to retrieve in case they fall into water. Below are some of the mechanisms used to make binoculars float:

  1. Air-filled chambers Some binoculars are designed with air-filled chambers inside the body, which creates buoyancy, allowing the binoculars to float. The air-filled chambers are strategically placed in the body of the binoculars to provide balance and stability, preventing them from tipping over.
  2. Waterproofing Most binoculars that float are designed with a waterproof casing. This is because, when the binoculars come into contact with water, they tend to absorb it, thus making them heavy and prone to sinking. A waterproof casing prevents water from seeping into the binoculars, thus keeping them afloat.
  3. Buoyancy aids Some binoculars come with buoyancy aids, which are attachments designed to keep them afloat. These attachments are either in the form of straps, floating collars or buoyancy bags. They are attached to the binoculars and prevent them from sinking in water.


Fogging and sinking are common problems that binocular users face, especially in extreme weather conditions. However, with the advancement of technology, manufacturers have come up with ways of combating these problems. The anti-fog coatings and nitrogen purging methods are effective in preventing fogging in binoculars. On the other hand, the air-filled chambers, waterproofing, and buoyancy aids are the mechanisms used to ensure that the binoculars float. The ability of a binocular to float and not fog up is essential, especially for activities like marine activities, which may involve extreme weather conditions.