We’ve all seen people who can’t seem to focus when reading and start holding their book or phone as far away from themselves as their arm will stretch. This is almost always down to one simple fact – age, or more accurately ‘old sight’. That is the definition of presbyopia and something that happens to us all. Simply put, it is a normal loss of near focusing ability that occurs with age, its main effect being a difficulty in reading small print. It generally occurs in people over the age of 40 and can mean a sudden change to the way we buy spectacles.
Anybody who has worn glasses all their lives may suddenly need to think about a multi-focal lens which will correct both their distance and near vision. Even those lucky ones who have never needed visual correction may now need help with reading. This could mean a single pair of reading glasses or, if they don’t want to worry about taking a pair on and off when required, a multi-focal lens could also be the answer.
So what is a multi-focal lens? This isn’t a simple one word answer I’m afraid, as there are a range of options available. The most common and well known lens may be the varifocal. This is a lens which becomes rogressively more powerful the further the eye moves down the lens. This enables the wearer to get clear vision at all distances and means they can just have the one pair of spectacles for all their needs.
A second option is the bifocal. This lens has been around since the mid 18th century when it was said that Benjamin Franklin asked his optician to cut his distance lenses and near vision lenses in half and stick them together. This gave him the ability to see at two focal distances while wearing just the one pair of specs. Technology may have moved on since then but the premise is much the same, with a reading segment located in the bottom half of the lens while the top section fulfils the wearer’s distance vision requirements.
In more recent years, occupational lenses have become very popular. This lens is often an excellent choice for a presbyope who works at a computer for long periods of the day. They enable the wearer to have sharp vision for both close up and intermediate work, whether that entails using a PC or some other device.
So remember, whatever your needs, there will be an option out there for you. Be sure to consider exactly what you do and don’t want your glasses for and most importantly, talk to your optician so they can help you make the perfect choice!