Everyday activities such as reading a colorful chart or selecting clothes can be difficult for those with color blindness. Most people with color blindness have trouble discriminating between red and green shades. Red-tinted glasses can help to enhance color contrast and perception in this case. The development of tinted contact lenses for managing color blindness has proved more challenging. Although prototype dyed lenses improved red-green color perception in clinical trials, they leached dye, which led to concerns about their safety. Gold nanocomposites, in contrast, are nontoxic and have been used for centuries to produce red glass—the red color being due to the way they scatter light.
Ahmed E. Salih, Haider Butt, Khalifa University, Abu Dhabi, United Arab Emirates, and colleagues have investigated whether incorporating gold nanoparticles into contact lens materials instead of dye could improve red-green contrast safely and effectively. To make the contact lenses, the researchers evenly mixed gold nanoparticles into a hydrogel polymer. The team used 2-hydroxyethyl methacrylate (HEMA) as the polymer, which was cross-linked with ethylene glycol dimethacrylate (EGDMA) using 2-hydroxy-2-methylpropiophenone as an initiator. They obtained rose-tinted gels that filter light within the wavelength range of 520–580 nm. Contact lenses made from this gel have water-retention properties similar to those of commercial ones and are not cytotoxic.
The gold nanocomposite lenses are more selective in the wavelengths they block than commercially available pairs of tinted glasses, and they match the wavelength range of previously developed dyed contact lenses without the potential safety concerns. According to the researchers, the next step is to conduct clinical trials with human patients to assess the efficacy and comfort of the lenses.
- Gold Nanocomposite Contact Lenses for Color Blindness Management,
Ahmed E. Salih, Mohamed Elsherif, Fahad Alam, Ali K. Yetisen, Haider Butt,
ACS Nano 2021.