Can contact lenses freeze to the eye or damage the retina in the cold? It sounds scary, but it's safe to say that it's not true. Do not rush to change lenses for glasses in winter, the lens will not freeze to the eye, will not damage it and will not lose its properties. This is ordinary physics, see by yourself.
A contact lens is called so because it fits closely to the eye. And therefore, according to the law of physics and being biocompatible, it has exactly its temperature, and not the air temperature at all. In this it differs from the lens of glasses, which does not adjoin the eye, is surrounded by cold air and can become very cold in frost. In addition, it is much thinner – most often no thicker than 1 mm. At the same time, the temperature of the eyes is close to the temperature of the body and is always approximately 35°C. In contact with the lens, the eye warms it, and the upper eyelid, due to frequent blinking, helps maintain this temperature in any frost. Therefore, it cannot freeze and stick to the surface of the eyes.
In addition, the material of all modern soft contact lenses (hydrogel and silicone hydrogel) is biocompatible. Perhaps you are assuming that this is something like glass. In fact, it is a soft, breathable material that is closer to plastic than glass, biocompatible, i.e. maximally "tuned" for interaction with the eye, including maintaining the same temperature.
The retina is the inner shell of the eye, which does not come into contact with the lens. Rays of light enter it through the pupil, and then they are converted into an electrical signal that enters the brain. The retina is responsible for our vision, so taking care of it is justified. But there is nothing to be afraid of. The contact lens is located not on the retina, but on the cornea of the eye. And therefore, it cannot affect the work of the retina in any way, since it is far from it. Agree, it would be wrong if such an important part of the eye would not be protected from contact with the external environment.
For all these reasons, frost itself does not directly affect contact lenses. But there are still features of wearing them in cold weather, in winter. The fact is that in the cold season the air becomes drier, which is a factor of discomfort when wearing lenses, causing a feeling of dryness and a foreign body in the eye. The same consequence is with heating, not on the street, but indoors. That is, it is not frost that is harmful in winter, but dry air on the street and in rooms. This is true, of course, for those who do not wear lenses, but for those who do, the situation is exacerbated. To avoid discomfort, it is recommended to use moisturizing eye drops, but they should be applied at least 15-20 minutes before leaving the house, no later.
Also, both in summer and in winter, for the safety of vision, it is worth protecting your eyes from ultraviolet rays. There is no less ultraviolet radiation in winter than in summer, and possibly more, since the sun's rays in winter are reflected from the snow. Therefore, it is worth giving preference to contact lenses with UV protection. True, keep in mind that they protect only the area on which they are located, that is, not the entire eye, and do not get carried away in the sun without sunglasses, including in winter.
And do not forget to follow rules for lens care and replacement terms, then neither frost nor any other external conditions will affect the health of your eyes and visual comfort in lenses .