Outside Looking In

[Jim A. Daul]

Greetings ~ Anyone have ideas on how to opaque a lens in one direction? The principle would be the same as one way glass. I have a patient with glaucoma and macular degeneration .. more comfortable to close an eye than to keep both open while wearing eyeglasses but impractical to do 100% of the time. Looking for a way to accomplish functually and cosmetically so patient can keep both eyes open with one eye opaque but transparent from outside looking in. I thought of putting a mirror coating on concave side but don't know if it would work ... I question whether it would be totally opaque. Suggestions and/or other solutions are appreciated.

[Jim A. Daul]

Found it !! It's called the Mins lens.

[fjpod]

You can accomplish almost the same thing by applying regular (or Scotch brand) invisible tape to the inside surface of the lens, neatly, as if you are applying a Fresnel. Diplopia is often transient and once the patient adapts, further occlusion is rarely necessary, and the patient will likely want to remove the occlusion to regain some peripheral awareness and depth perception. ...might make the Mins lens a costly excursion in futility.

[Darryl Meister]

The principle would be the same as one way glass.

One-way glass or mirrors rely on a partially reflecting surface with reduced illumination behind the glass (the glass is actually transmits light equally in both directions). So it really wouldn't be an option for your application.

I am not familiar with the Mins lens, but I imagine that inducing significant optical defocus may be one reasonably practical method of degrading vision with an otherwise clear lens.

Fjpod has also provided some great feedback.

Best regards,
Darryl

[MakeOptics]

A bangerter foil or filter is the equivalent professional device to scotch tape. Unfortunately it is opaque from both directions but it would accomplish your goals. You could also ask your lab to skip the polishing step and only fine with a two step process during surfacing this will leave the lens frosted as well.