Ophthalmology

Contact Lenses for different purposes 
Contact lenses for correcting refractive error are designed to improve vision for patients with refractive errors such as near-sightedness (myopia), far-sightedness (hyperopia) and astigmatism. Beside monofocal contact lens, toric and multifocal contact lenses are now also available to correct astigmatism and presbyopia. 

Multifocal contact lenses are available to correct presbyopia. The lens has multiple prescriptions in one lens, allowing wearers to see clearly at different distances. They are in many different designs. The most common design is a set of concentric circles of lens powers prescribed for various viewing distances. Multifocal contact lenses can give you acceptable vision for most of your daily activities but you may still need glasses for specific tasks such as driving at night or reading small print. 

Keratoconus contact lenses improve vision for patients with keratoconus. Keratoconus is a progressive, debilitating eye disease characterised by degenerative thinning and protrusion of the central cornea, leading to distorted vision. Symptoms include photophobia, visual distortion, halos around lights, ghosting and glare, decreased vision, and monocular diplopia (double vision). While spectacles and soft contact lenses cannot correct vision caused by keratoconus, most individuals can achieve functional vision with therapeutic rigid gas permeable (RGP) contact lenses. These uniquely designed lens improve vision by providing a clear optical lens that masks the distorted areas of the cornea to create a smooth, regular optical surface over the patient’s irregular, cone-shaped cornea. 

Orthokeratology (Ortho-K, OK lens) are specially designed RGP contact lenses that alter the shape of the cornea for temporary correction of low degrees of myopia. They are usually worn overnight while sleeping, these lenses gently reshape the cornea, improving vision during the day without the need of glasses or daytime contact lenses. However, the cornea gradually returns to its original shape after discontinuing Ortho-K lenses wear for a few days, leading to the recurrence of refractive errors. While Ortho-K lens offers a convenient vision correction option, it is important to be aware of potential risks associated with overnight wear. 

Prosthetic contact lenses are contact lenses that are made to assist patients who have experienced serious eye injuries or diseases that have altered the appearance of their eyes. These lenses are made with colour painted on them. The lenses can be designed as simple as a solid colour to an advanced painted iris-like design to look as much as the natural eye as possible. These lenses can cover up any scarring or disfigurement on the cornea, helping to improve the appearance of their eyes. Prosthetic contact lenses can also help people with aniridia or albinism by reducing their sensitivity to light.

Without prosthetic contact lens

With prosthetic contact lens

Therapeutic bandage lenses are a type of extended wear contact lens used as bandages for various eye conditions that cause eye pain. They are used to treat conditions such as corneal abrasions after injury, recurrent erosion, bullous keratopathy, or post-corneal surgeries like phototherapeutic keratectomy. These lenses promote corneal healing, serve as a protective barrier, and reduce discomfort caused by friction from blinking during the recovery phase. Bandage lenses are primarily made of silicone hydrogel, a material with high oxygen permeability that facilitates corneal healing. Unlike other protective options, such as pressure patching, bandage contact lenses allow for easy medication administration to the eyes.