Whether or not one should delay cataract surgeries when vision does not seem to be significantly affected depends on a few factors:
1) MOST IMPORTANTLY, WHAT IS YOUR RISK OF ANGLE CLOSURE GLAUCOMA
It can be terribly confusing to many, including to some eye doctors themselves, but cataracts are associated with a type of glaucoma that is more common in Asians called angle closure glaucoma. And in case you have not heard about glaucoma before, it is an irreversible eye disease often referred to as the thief of sight, that is best prevented rather than cured, as damage done cannot be reversed.
If you have long-sightedness (as opposed to short-sightedness and presbyopia) you are at higher risk of angle closure glaucoma. Long-sighted eyes are generally eyes with smaller internal dimensions and the lens thickening that comes with aging are more prone to crowding the outflow channels in these eyes versus eyes with larger internal dimensions (axial length).
Quoting the 2017 edition of the Principles of Preferred Practice in Cataract Surgery published by the APACRS (pardon all the jargon): "Removal of the clear or early cataractous lens in primary angle closure/primary angle closure glaucoma reduces the forward bulge on the iris and leads to deepening of the anterior chamber, opening up of the angles and improving the long-term control of intraocular pressure (IOP) in these eyes".
Ask for a "gonioscopy" which is an examination of the outflow angles of your eyes. If they are very narrow you are better off having your cataract surgery sooner rather than later.
2) Are your daily activities affected by your drop in visual function? If yes, it is fair to consider a cataract surgery already
3) This may not sound diplomatic at all, but although the success rate of cataract surgery is generally high in Singapore, skills may vary between surgeons, and results also depend on what type of intraocular lens implants one chooses.
Ask about the size of wound of the proposed surgery, the smaller the size (it can be as small as 1.8mm) in general the faster the recovery will be. Also, pricier lens implants (e.g. multifocal or extended range lenses) are able to deliver a wider range of good vision, possibly eliminating the need for glasses afterwards.
I suggest finding out more about your eyes, and when the time comes for cataract surgery, do discuss your visual requirements with your doctor.
