hard lens

Related to hard lens: soft lens

hard lens

n
(Medicine) a rigid plastic lens which floats on the layer of tears in front of the cornea, worn to correct defects of vision. Compare gas-permeable lens, soft lens
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014

hard′ lens′


n.
a contact lens of rigid plastic or silicon, exerting light pressure on the cornea of the eye. Compare soft lens.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
Historically, hard lens wearers have tended to drop out of contact lenses as they become presbyopic because their eyes can be much drier.
polymethylmethacrylate (PMMA) (hard lens), hydrophilic acrylic foldable IOL, hydrophobic acrylic foldable and silicone gel.
Aquapac Mini Camera Case with hard lens 35 [pounds sterling]/63 grams
Having made this discovery, lens manufacturers began to research and develop a gas-permeable hard lens that was designed to be used only at night.
Once the droplet assumes the desired form, a few minutes under an ultraviolet lamp polymerizes the liquid into a hard lens.
Finally, Swanson encourages us to look at our own positions of privilege as she casts the same hard lens upon herself.
But with our expansion budget of $3.2m, the Fred Hollows Foundation intends to start manufacturing this foldable (soft lens) while increasing production of the hard lens five fold."
The contact lens care portion of this category continues to decline steadily in terms of both hard lens care and soft lens care products.
RainGuard is a unique, hard lens coating that disperses water molecules, forming tiny little beads of water on the lens surface instead of large droplets, allowing for better light transmission and target acquisition in rainy conditions.
That compares with $5.6 million for the top 10 items in the hard lens category and $34.7 million for the top 10 products in the gas-permeable segment.
The relatively new soft hydrophilic -- water-containing -- lens affords patients the advantage of instantaneous comfort, unlike its predecessor, the hard lens. The wearability of various types of contact lenses depends on the amount of oxygen that can be transmitted through the lens.
They found that the hard lens could alter the shape of the cornea, helping to slow down any deterioration in eyesight.