Silicone Hydrogel Lenses
Another category of lenses that are fairly new to the market are the silicone hydrogel lenses. These lenses can provide many times more oxygen to the eyes compared to other category of lenses. These lenses are actually providing some patients with a second chance to remain in soft contact lenses. If there is a significant risk of failing ocular health due to lack of oxygen to the cornea, then these lenses may provide the needed oxygen and therefore may extend a patient’s ability to remain in soft lenses.
Bifocal & Multifocal Contact Lenses
Just as the name indicates, bifocal lenses are divided into two distinct segments for different vision powers, the first for distance vision and the second for near vision. This enables you to clearly switch your focus from near to far as needed, but your vision will not necessarily be clear in between. The term multifocal lenses can refer to any lenses with multiple powers including bifocals, trifocals or progressive lenses. Non-bifocal multifocal lenses have a range of powers that enable you to constantly adjust your focus to see clearly from up close to far and in between.
For those patients that have had a difficult time finding lenses that provide good enough vision for their lifestyle, there are RGP or “hard” contacts. These lenses do provide better vision in most cases, but are usually a bit more diffcult to adjust to comfort wise. There are many patients in these lenses that are completely happy and unwilling to switch to soft contact lenses.
Toric Contact Lenses for Astigmatism
Toric contact lenses are designed to correct astigmatism and custom made to fit the eye of the patient. Rather than having a perfectly spherical surface like standard contact lenses, toric lenses have a more oblong shape made to accommodate the shape of the astigmatic eye. Toric lenses can be made of either soft or rigid gas permeable (RGP or GP) lens material, however the soft toric lenses are more common.
Toric contact lenses are also designed in such a way that the lenses stay in place on the eye to maintain proper vision. Sometimes as the eye moves or blinks the lens can rotate considerably on the eye. If this rotation continues with a soft toric lens, a rigid gas permeable lens might be more effective. Rigid gas permeable lenses have a longer initial adjustment time, but once this has passed they are usually just as comfortable as soft contact lenses and they are often easier to care for.