The new Essilor Eyezen lens is clearly being aimed at patients suffering symptoms linked with digital eye strain. When I saw recently such a patient, I thought it too good an opportunity to miss to try out the new lens.
Patient presentation
The patient is female with a date of birth 7/8/1974 and appeared to show signs of incipient presbyopia (feelings of strain especially in the evening – ‘for eBay’ – figure 1) along with digital eye strain (the same when using a tablet or smart phone accompanied by grittiness and blurring on blink exclusive to screen viewing).
She only recently had increased evening tablet use, which could be anything up to three hours at any one time. Typical working distance 50cm.
She was anisometropic and had had spectacle and occlusion treatment when aged five to seven years, and had worn spectacles sporadically (‘for concentrating’) until aged 35 when she started wearing one-day silicone hydrogel lenses full time (R; +2.00, L; +3.00). Apart from the reported symptoms, vision and comfort are generally good with contact lenses and she was very resistant to the idea of spectacles.
Health was good. Patient is a regular smoker of around 20 cigarettes a day.
Refraction:
R: +1.75DS (6/4)
L: +3.00/ -0.50 x 90 (6/5)
N5 (R and L) to 20 cm
Cover test showed orthophoria at distance and near and near point of convergence was ‘to nose.’
There was evidence of significant tear instability, with conjunctival and corneal desiccation, irregular tear prism and a fluorescein tear break up averaging four to six seconds on repeat (figure 2).
Figure 2: There was significant evidence of tear disruption
All other clinical findings were unremarkable relating to this case.
Discussion
A few points need to be considered. Prescribing the first reading addition may seem an easy choice, but it is worth remembering that in some cases this may reduce the already existing ability to accommodate the required amount.1
On the other hand, a sudden increase in near digital task work can trigger symptoms and contribute to what is now established as the condition ‘digital eye strain.’2 Even though accommodation here should be adequate, a small addition along with advice regarding positioning and lighting should help with the visual symptoms. To be sure this would help it was absolutely essential to confirm the patient was orthophoric at near as any exophoria in a symptomatic patient may actually be made worse by the introduction of an addition.
Contact lens wear is likely to be exacerbating the impact of tear film disruption and evaporation and the patient is now fully aware of the need for regular breaks when viewing screens, improved blinking behaviours, hydration measures, and also that, as well as linked to the other well-known concerns, smoking is bound to be aggravating the discomfort.
The use of a small addition spectacle lens, it seemed to me, offered an opportunity to encourage better visual stability in the evening, not only by removing contact lens influences altogether, but perhaps helping improve the pre-ocular humidity.3,4,5
Dispensing details
- The above prescription was ordered along with the +0.60DS addition option Eyezen lens.
- Frame chosen offered fitting heights of 23mm R&L (minimum 18mm recommended)
- Mono CDs were R 31mm L 32mm
- Face form angle was 4º (this must be a positive
- value)
- Pantoscopic angle was 8º (between eight and 12º is recommended)
- BVD was 8mm (8 to 10mm is ideal)
Outcome
The patient is happy to continue with daily contact lens wear and use her new spectacles for her evening work. The symptoms have subsided significantly over the month since wearing the spectacles.
I feel this option was perhaps the most sensible and will review in two years with a particular interest in introducing presbyopic contact lens options along with supplementary low addition spectacles for periods of non-lens wear.
Further information on the Eyezen lenses from essilor.com.
References
1 Vedamurthy I et al. The influence of first near-spectacle reading correction on accommodation and its interaction with convergence. Investigative Ophthalmology and Vision Science, 2009, 50(9): 4215–4222
2 Rosenfield M. Computer vision syndrome aka digital eye strain. Optometry in Practice, 2016, Volume 17: Issue 1, 1 – 10
3 Nichols J J, Ziegler C, Mitchell GL, Nichols KK. Self-reported dry eye disease across refractive modalities. Investigative Ophthalmology and Vision Science, 2005;46:1911–4
4 Tsubota K, Yamada M, Urayama K. Spectacle side panels and moist inserts for the treatment of dry-eye patients. Cornea, 1994, 13: 197–201
5 Henderson R, Madden L. Dry eye management. Optometry in Practice, 2013, Volume 14, Issue 4, 137-146