Visual Impact

Dr Rajan Chugh elaborates on new lenses for ‘super’ vision

Intra Ocular Lenses (IOLs) have made tremendous impact on the visual outcome following cataract surgery. Reading all lines on the vision testing chart,that is 6/6n or 20/20 is not the only parameter of perfect visual gain,other things that constitute quality of vision like contrast sensitivity and form of vision with projection of proper hues and tackling and removing visual aberrations also form important components of quality of vision. The advanced lenses are aspherically designed and have no aberrations that retard or blunt the quality of vision and contrast sensitivity in routine lenses. Thus,these aspheric lenses give exceptional vision quality that enables a person to see clearly in fading light/during night driving and under foggy conditions,to mention a few oddments and thus aim to provide a truly ‘super’ vision. The colours of the objects appear most natural,sometimes even better than natural lens. The vision is sharper and crisp. The anti-glare feature adds to the comfort. They also give enhanced depth of field of vision. These are more stable inside the eye and appear/behave as more natural with no hint of artificiality or reaction. In some lenses the lens surface has been treated by materials so that formation of Posterior Capsular Opacification (PCO) following cataract surgery becomes less and appears quite late. Some lenses have ultra-violet (UV) protection that helps in cutting harmful affects of sun rays just like sunglasses. There are many designs of IOLs that make them stable inside the eye with negligible chances of (early or late) decenteration or dislocation. Another remarkable advancement in intra-ocular lenses is success of multi-focal lenses that give clear,workable vision at all distances — near,intermediate and far under all conditions and obviate the use of spectacles even for reading to a larger extent; in the process also making general intermediate distance jobs comfortable. As we know,there is an adjustment problem in using bifocal/multifocal/varifocal (progressive) spectacles,not all patients require these,thus not all patients require multifocal lenses with Phacoemulsification operation. But in carefully selected and counselled patients,they are tremendously useful. Your eye doctor is the best person to judge this factor for your eyes.

It is important to understand that near vision is not just about reading at close distance and is required only in office-goers but is also about doing domestic chores like shaving,reading caller’s name on the mobile,doing make-up standing before a mirror while going to a kitty party. All these new-generation IOLs try to give visual benefits comparable to natural God-given lens. Patients with high astigmatism,the cylindrical error get benefit from toric intra-ocular lenses. With advancing age,and slow nature of deterioration of vision with formation of cataract,most patients don’t realise and appreciate the decreased vision attributing it to normal and natural decrease with age,and are surprised with the amount of vision they get after phaco-emulsification.

The writer ia an eye surgeon & laser specialist